It's the same with "The Village" when deciding not to have kids. Everyone is allowed to move back to their hometown, or ask family to move closer. It's not always simple to do, but it's a choice people make not to.
I could take a $200,000/annual pay cut to move back to my hometown and live in an area devoid of things to do; but, you're right: I chose to move away and live somewhere that offered my children things I did not have and thus choose not to do that. I am also not sure how I could have my parents make the choice to live in an area that's more egalitarian and diverse; however, you're right, again: they choose not to.
If you have the privilege of a $200k delta then you have the middle ground of buying your parents a house near you.
I already pay for the house I no longer live in but my ex-wife does as well as my own with a 7.6% APR. But, them not having a house has nothing to do w/it; they don't want to live somewhere like this.