So, we have now seen Boston. We have seen the DC Wasteland. We have seen Point Lookout and Pittsburgh. We have also seen how the West Coast started to rebuild properly prior to Fallout 2; NCR/Shady Sands having proper buildings and even some advanced tech (laser fields), Broken Hills looks actually rather pleasant, and even in the original Fallout we can see sandcrete buildings. Sure there were the occasional settlement that was corrugated steel shacks and barely standing remains of pre-war towns, bit it felt like these were starting to become less the rule. Even then, they had at least bothered to take the skeletons out of their bathtubs, or their beds. Vegas may have been largely spared the bombs due to House, but it still feels like it has been somewhat maintained. Others have chosen to go Tribal, and live well off the land, making clothes and living in proper tents and such.
So... what went wrong on the East Coast (and yes, I know the answer to that is Bethesda design choices, but I'm trying to hash out a reasonable possibility in canon)?
In DC it was easy to justify how everyone lived due to the state of the area; raiders being the majority of the population, preying on eachother, and those few who wanted to live normally. Add super mutants, and other wasteland threats, with a sprinkling of 'DC being what it is, only recently got resettled in any major way'. So I could justify it to myself in FO3. They are where the wasters of the original Fallout were; and to their credit, the 'normal' settler did clear out the bodies if not the junk piles. Rivet City is cluttered, but overall seems relatively livable.
Now, Maxson says that on the way, they saw cities overrun by mutants and abominations,where humanity has no footholds. But... that doesn't really explain the Commonwealth. Sure, synths, super mutants, and a particularly large population of ghouls, yadda yadda.
It's been 200 years, and the Commonwealth wasn't half as dangerous as it became until the last, what, half a century? Diamond City is tidy enough; but not only does it not even fill the stadium, and they haven't got the numbers to build vertically, even if we put aside gaming downscaling - there is a limit to the size of a settlement you could fit into a baseball stadium and then sustain, considering the need to leave a large part for farming. And this is the biggest settlement in the Commonwealth when you arrive. Goodneighbor is maybe a city block; it's Hells Kitchen, Boston. Quincy is much like it, presumably. The Fort was a militia base. Other settlements are small by design. Farming settlements and communities that self sustain.
Boston seems barely settled, really, even compared to the CW. And Boston still has functioning factories.
But, this isn't what I find hard to get my head around, really. It's the 'cultural mindset'. When a settlement is established, people seem to settle for living basically like pre-war homeless, as though it's not the case of a bit of hard work to do better. They live in shacks, usually surrounded by piles of trash and rusted skeletons of vehicles (that are even potentially explosive), and sometimes don't even bother to clean out the bones of the long dead. I haven't found a single shack that would actually keep the weather out; with holes in the roofs, no windows, and sometimes no doors, they are basically fancy bus shelters. In an area with severe rad storms that can roll in any moment. It's like as a culture the people on the East coast are the walking dead. They are resigned to... everything and anything terrible.
The thing is, this is likely to continue, because out of lore for a moment, it's how Bethesda feel the East should look for that post-apoc feel. And I feel it's getting harder and harder to understand in the lore.
How do you guys and gals wrangle this when trying to roleplay? I think it's especially relevant to Fallout 4, as our character has seen the world before. America itself has only been around a little longer in real life than the time since the bombs dropped in Fallout, and look at the progress.