system
Given the following post, respond as if you're commenting on Reddit:
human
[Fallout] Why is the East coast so much less developed than the West coast in terms of organized society?

It's population was roughly the same, if not greater, than the West coast and it had plenty of vaults of its own so population shouldn't be a problem. The West coast doesn't appear to have much more infrastructure. While the commonwealth makes sense given the presence of the institute but what about the rest?
gpt
Remember that we've only seen a few TINY glimpses of an utterly massive half of the country. There might be some rather large and organized parts of the east coast further south, but communication and trade are just starting to become commonplace beyond small local economies. 

Washington DC was hit especially hard by Chinese nukes, because it was the seat and symbol of America's power. China targeted it with a huge number of small tactical nukes and dirty bombs meant to poison the landscape forevermore. They wanted to utterly destroy America's heart and make sure it NEVER rebuilt no matter what. Because of this extensive and brutal bombing, the Capital Wasteland is more barren, broken, and poisonous than other areas. But as we've seen, there is hope. Oasis might spread in the coming years. And Project Purity will eventually fix a major part of the local water supply. With the Brotherhood of Steel firmly in charge, it's very possible DC will soon be the capital again, but of a BoS government. 

Boston was not hit nearly as hard, and is in fact remarkably intact after two centuries of neglect. But still, the radstorms that come from the glowing sea keep the local area full of deadly radiation. And thus keep mutations, cancer, and other deadly afflictions constantly in the living populations. We know that people in the area have certainly tried to set up local governments and organize themselves. But the Institute destroyed the last attempt (but from their perspective, they tried to set it up in the first place and petty issues destroyed it). And the Minutemen fell apart because of weak leadership and constant infighting. 

Similar to the issues with the glowing sea, the tiny glimpse of Maine we've seen is full of regular cycles of incredibly deadly radioactive fog. It's impossible for people to live and prosper there without extensive technological aid. 

Also, remember that the NCR would never have existed without the aid of the legendary Vault Dweller. And then, it took decades after the dweller's actions for it to become a large stable power. It's only been ten years since the Lone Wanderer helped stabilize the Capital Wasteland, and the Sole Survivor is still doing stuff around Boston as far as we know. So perhaps in 50 years, we'll see some kind of massive change in the local area.