This gets into one of the more difficult issues of Bethesda's games, which is the fact we can't really say what is literally true versus metaphorically true in terms of the settlements. The Republic of Dave is literally meant to be Dave, his harem, and his children. That's the joke. Arefu is also probably only a small number of citizens because the Lone Wanderer can single handedly kill them all. However, I don't think Megaton, Diamond City, or Rivet City is meant to "literally" just be the citizens on screen. Diamond City is the "Jewel of the Commonwealth" with a class divide between the Stands and the Grounds. You can't really do that with just fifty people and there's often references to other groups. I'm inclined to give it a population of about 5,000 people with the idea of 1 settler=10 people in terms of real numbers but this is just my idea of the whole thing.
Yet, ironically, I would think the Super Mutant and Raiders settlements are "literally" true. It's like Skyrim where you can wipe out a Bandit Settlement single-handedly and that makes sense but Whiterun is probably more than the few streets you see.
Honestly, I felt the Commonwealth felt much more settled than the Capital Wasteland. Dozens of (small) villages and trade routes to one gigantic town.
Which isn't hard, considering that the Capital Wasteland has been a war battlefield for decades, and the main target for the nuclear warheads. Managing to do just a little better than them is not an achievement, in my mind.
If 1 settler = 10 people, then Diamond City would have about, let's say, 5000 to 10 000 citizen.
Which would make it the same size as the refugee "camp" of Calais, commonly called "the Jungle of Calais", which actually has about the same amenities than Diamond City : makeshift schools, shops, restaurants, church etc.
The guys at the jungle don't speak the local language. They don't have money, resources to salvage, things to trade or anything. They are secluded and hated by the local population. They don't even want to stay in France, so it's not like they actually even "wanted" to build a shanty town in the first place.
Guess how long it took them to build one, roughly the size and structure of Diamond City (aka, "the jewel of the commonwealth", or a shanty town, depending on the point of view) anyway? Not 200 years, no. Three months. Three freaking months. Which illustrates my point : when it comes to build our home, humans are impressively fast and effective.
Strange that it took two centuries for the local population, in their own town, with plenty of junk around to salvage, two entires centuries to build something that foreign refugees took only three months to make, litteraly by accident.
Second problem : let's imagine that 1 settler = 10 people, alright. This optimistic scenario leads to another problem. Let's see the calculus for population's growth rate here...
And alright, let's do some math. Let's consider that Boston roughly had 650 000 citizen by the time the bombs fell, aka approximatly as much as today's Boston. Seems plausible.
Now, Diamond City, with its 10 000 citizen, make up for most of the town's population. Let's add 50%, because of raiders, traders, goodneighboor and lowlifes living here and there. We get 15 000 people. Seems highly optimistic (Super Mutants wouldn't last long if that was the case, considering that unlike humans, they can't replace their fallen comrades), but anyway.
Growth rate (in percentage):
= [[(15 000 - 650 000) / 650 000 ] x 100 ] / 10
= -0.97 x 100 / 10
= -19%
Let's compare that to the growth rate of Europe during the black plague's century, which killed more people than a nuclear war could : -0.07%.
See the problem, there ? In two centuries of average peace (aka, no large scale conflict or invasion) and reconstruction, the growth rate is 271 times lower than Europe's DURING the black plague. Hell, with -19% of growth rate, the commonwealth should be populated by inbred, prehistoric tribes by now. Oh, what's that ? New Vegas and Fallout 2 seem to have taken the the growth rate into account, when building their lore ? There ARE actually tribes in places where the growth rate is impossible to rise, such as arid environments and canyons ? And in civilized, fertile lands, there are millions of citizen living in city states, with different functional societies, businesses and agricultural trade, who have stopped "surviving" a hundred years ago ? Oh.
So, I'm okay with that. I'd roll with any explanation for why the Commonwealth is basically empty. Maybe there's a big problem of sterility due to radiation (which would actually JUSTIFY the construction of Synthetic humans in every way, but nooo, it's not like the writers thought about synthetic surrogate mothers, which would make perfect sense for the Institute). Maybe there has been a virus that decimated the population shortly before the events of Fallout 4 (which would give importance to Curie's experiments, but then again...). Maybe there has been another war that has forced people to move away (which would enhance the history of the Minutemen, but no)
There could be plenty of perfectly plausible explanations. Thing is, we get none, because the writers simply didn't think about it. In seven years of production. Instead, they boast about "an obsession to details" because they took some time to render different shades of Pipboy's buttons, and they don't want to discuss realism in a world "with talking mutants".
so, Mister Phipps, did you ever make it to the Cathedral?
Hag, I love your signature. It's okay to have a crush on the master. It's not dirty.
