They might as well use the licence to make a great spin off instead of a mediocre "RPG"
What a waste of good franchise. I pity those who were willingly threw money so easily on whatever Bethesda made using the Fallout name. They certainly didn't get what they were supposed to get when they buy a product that bears the 'Fallout' name.
I know what you were trying to say, but it's pathetic we have to come to this when discussing the possibility of where the franchise is going. It's one thing to discuss if we are ready to let go and hoped for a 'replacement'. It's another to discuss whether we would be 'okay' if Fallout keep going further and further from what it was supposed to be.
Besides, we're talking about Bethesda here. The FPS mechanic of Fallout 4 were thanks to id Software, so to make full-fledged shooter Bethesda aren't even competent there. Hell, even as hiking simulator people admitted they are getting bored because of the lack of content and repetitiveness of it.
Like many said here, what you said 'might' work, but there's lots of competition in that market. Remember, all these times Bethesda managed to get by because their mix of everything was kinda 'unique' and there's no one else is trying to do what they were doing, hence they tried to please as many people as possible. If they try to focus on just one thing and, therefore, pleasing only one kind of audience, they would lose miserably.
Not only that, if we are to follow your advice and have the entirety of settlement building tied to the game-world, attempting a world building like trying to find the Institute spy among your settlers, that would require good writing and proper narrative design, and you know how shitty Bethesda is in that department, right?