Makes perfect sense. Those thirteen colonies were built on genocide, with slavery and support from existing European empires. Without those, particularly the first two, the US is nothing. Bethesda is holding up a mirror: this is what you would achieve without socialism, America, if you couldn't exploit the resources, strength, and minds of those you have oppressed for centuries.
As great as that would be, I think you're really giving them too much credit. Fallout 4 is shanty towns because Fallout 1 and 2 were, that's as much thought as went into it.