-So was both Washington D.C., and Boston, and yet they managed to do just fine. Even Tuscon was able to rise up as something of a civilized town, despite the fact that, according to Raul, Arizona was so thick with raiders it was impossible to trade two miles down the road, which is far worse then D.C. or Boston. On the other hand, Vegas had the benefit of not being hit by the bombs, having a massive amount of fresh water and farmable lands, and having basically no raiders. The idea they degenerated into tribals in the first place is absurd, but the idea that they didn't manage to build anything in Vegas, despite having everything, while literally every other major city that wasn't just leveled during the war managed something, is nonsense. And, House rebuilt the strip, and the casinos, before the NCR started arriving. They didn't get money from them to fix the places up and make them operable. They had to be operable in the first place for the NCR to spend money there.
-Actually you kind of do since the game is full of invisible walls and monster walls, and all the major problems in places like Goodsprings, Primm, Novac, all are framed around asking where did Benny go, and them giving you some task to complete in exchange for the information. The game literally forces you to go after Benny. And the things you listed about the deathclaws and Black Mountain are, like the rest of the game, level locked to a level you can only really reach once getting past the 188 Trading Post, and at that point you have no logical reason to detour back to the starting areas to do those thing when Vegas is in your sights.
-Nothing you do in places like Goodspring, Primm, Novac, or Boulder City make you some idealized champion worthy of being the NCR or Legion's top dog agent. You don't even have to high tail it to Vegas, even if you follow the natural story path, nothing you do is really that big of a deal to make you the first pick for diplomat.
-And the BoS just recently arrived in The Commonwealth, and yet they are actively trying to pacify raiders, super mutants, and ferals. The NCR is just sitting around with their thumb up their ass until you come along. They can't even be bothered to investigate a town on fire because they are just so comic book cliche, pants on head retarded, inefficient at everything they do. Which is why its impossible to take the claim that they are good for the mojave impossible. They dont do anything, they largely don't even try. All because they tried to make a point with the NCR, that democratic systems have terrible problems with corruption and inefficiency slowing them down, but took it so far it moved past the realm of plausibility.
-The Legion is behind
--The Khans attacking the NCR
--The Fiends attacking the NCR
--Are making deals with the Van Graffs to attack the NCR
--Have been secretly funding the Omerta's plan to gas the strip
--Have been secretly working to revert the White Gloves into cannibals
--Are behind an attempt to bomb the NCR's monorail, which is achieved though a spy they had implanted in the NCR's ranks before the NCR even knew The Legion existed.
--They radiation bombed Searchlight
--They massacred Nipton
And that's just the stuff I recall off the top of my head. The Legion is behind damn near every single thing going on in the mojave that is even worth mentioning. Its this utterly ridiculous conspiracy, only achieved because they are just SO good as spying/infiltrating/convincing people that they cannot be matched, at all. Like a good mustache twirling villain is.
-A list of how House has shot his whole plan in the foot
--Despite waking up from his coma years before Shady Sands was even founded, he did nothing to try to organize the people around Vegas, thus ruining literally over a century's worth of buildup he could have had. Hell, House could have BEEN the NCR instead of needing to leech off them.
--Then, when he finally does decide to do something, its at the very last minute possible, forcing him to rush his defenses to hold back an oncoming army. Which only weakened his overall position in his dealings with the NCR. Something that could have been avoided had he done something in the 100+ years he was just sitting around with his thumb up his ass.
--Then, when he does actually make his city, he throws everyone who wouldn't immediately play ball into ruinous slums around his city, making everyone hate him, and making his already weak hold on the city even weaker, since even the people in Vegas hate him. This could have all been aovided had he done the logical thing, and elevated the first tribes who stepped forward into the three families position, but also worked to help everyone else in the city to not have to live in such shitty conditions. Even the real world Vegas has a small armies worth of average Joes to keep it running.
--Then, when it comes to running his city, he takes the worst, most hands off approach possible. Which only causes the Omertas, Whie Gloves, and Chairmen to scheme behind his back, because no one likes being ruled by someone who apparently couldn't give less of a shit about you. This is something any businessman could tell you would happen if you took that approach.
--Then, when it comes to his platinum chip, he idiotically sends one of his own, easily identifiable, and trackable, robots, to make a contract with the Mojave Express, and places an incredibly suspicious order to several seemingly random items, which only makes finding the plat chip increadibly easy if you knew what to look for.
--And, because of all this, at the start of New Vegas, House is in a city where everyone hates him, his own chosen Three Families have betrayed him, his own handpicked successor Benny has betrayed him as well, and stolen his mcguffin, and he is facing down two armies he has no chance of beating without the literal deus ex machina random event hat allowed The Courier to survive being shot in the head, and possibly make it to Vegas to work with him. Something that's not even guaranteed The Courier would do.
House is a grade A idiot, and nothing he has done makes sense, and has, in fact, been entirely defeatist to his whole plan. There is no reason for you to want to help him given his obvious inability to do anything right.
-Everything you listed, with he exception of the Boomers, comes from the NCR, and only proves my point. The Mojave has no history of its own, it just has a bunch of people from the NCR who showed up in the last 7 years. Even towns like Goodsprings were made by NCR citizens being given land grants.
-Except even Sawyer has stated that the Courier has little to no reason to go after Benny, and that they should have let you leave the region via the mojave outpost. The game's own lead writer has self admitted there is no reason for The Courier to go after Benny.
-But the problem is that those areas with deathclaws, such as at Quarry junction, are very obviously placed to serve as a barrier to prevent you from just going to Vegas. Which makes it feel unnatural. Places like the Deathclaw Promituary on the side of the map, or that Dead Wind Cavern, THOSE are natural placements of deathclaws. the monster wall of Deathclaws and stuff just north of Goodsprings/Quarry junction is just fake feeling because of how obviously it was just placed there to prevent you from reaching Vegas.
As for Fallout 4, it makes sense the stronger stuff would be at the bottom of the map, because the bottom of the map is the Glowing Sea, and a swamp, the two places with the least amount of human habitation, and thus, the most wild places in The Commonwealth, where the larger/stronger creatures would logically be.
-Nothing you said about the factions not making you a Legate, or General, has anything to do with what I was talking about. At all. You aren't proving yourself to the factions as you do the main quest, you are doing the main quest because you already, somehow, proved yourself to them, which is why they are giving you these major tasks. The point was that you don't really do anything, even by following the main quest line, to be considered worthy of being given that honor.
On the other hand, in Fallout 4, you prove your worth just to get in, and get higher ranks because you prove yourself over the course of several major and important missions for those factions.
-I already did explain it
-When it comes to the factions themselves, while Fallout 4 didn't provide as much information about them, I felt they were better handled.
---The BoS are massive racists, but at the same time we actually see them going around the map, their PA soldiers easy cleaning the wasteland of terrors such as ferals, and super mutants.
---The Institute are said to do all this evil stuff, but when you get to The Institute itself, you find out most of it is made up paranoia of the suerfacers. Many people in The Institute express clear remorse over the lives the people on the surface have to live, even if they aren't willing to help them due to past attempts failing.
---The Railroad were effectively terrorists, and were largely responsible for much of the synth paranoia in the region due to them placing mind wiped synths into the general populace, but they otherwise had a noble goal of trying to free "people" who apparently had actual sentience from a group of basically slavers.
The difference between New Vegas and Fallout 4 is that in New Vegas
-The NCR are just terrible at everything, period, and can't manage to put on their own pants without falling over and needing your help.
-The Legion are nothing but unrepentant rapists/salvers.
-House is just a jackass whose every action since the war has been self defeating.
-Yes Man is just holding the Mojave hostage with robots.
While in Fallout 4
-The BoS are bigoted assholes. But they actually get shit done, and actually make the wasteland a better place, even without your help.
-The Institute has done a lot of terrible stuff(supposedly), but once you reach them you see they have accomplished a lot, that most of the terrible things they are supposedly responsible are not their fault, and that they actually have some sympathy for the people of the surface.
-The Railroad are terrorists, willing to do a lot of shady shit to achieve their goals, but their goals serve a noble purpose of trying to free people from slavery. And they have managed to do so while fighting against the most technologically advanced faction on the East Coast for 20+ years.
-The Minutemen, while lacking organized leadership, and prone to internal squabbles, are a coalition of people, working for the betterment of everyone. And had lasted over a century, and gotten a lot of stuff done, before collapsing.
Fallout 4 strikes a far better medium between factions having problems, but also being able to do stuff. The factions in New Vegas are just unable to do anything(NCR), unrepentant evil(Legion), stupid(House), or dictator(Yes Man). New Vegas's faction are just so lopsided it hard to see them as beliveable things. They are almost so one sided that they come off as caricatures of the thing they are supposed to be.