Earlier quoted context omitted.
As an American I strongly agree with your insight, and independently arrived at it. It is an underlying cultural issue -- a lack of community spirit that is relatively widespread. It is a universal human tendency that is strongly in effect here at the current time and place.
> a lack of community spirit that is relatively widespread. How did this happen?
That desire for exclusion and enforced superiority appeals to some more than others. So it's unsurprising to me that HOA boards frequently turn out awful.
Happily, as older, first-ring suburbs turn into cities in their own right, we're seeing some reversal of that. E.g., as kids and grandkids stay in the area, we're seeing demographic and income diversification. Some places are realizing that things they've previously excluded, like drug treatment and publicly supported housing, are now necessary.