>yet I still disagree loudly with development in cases where it significantly harms middle-class communities in nice places that people have worked their whole lives to live in, and I am called NIMBY as an insult for it
It sounds like you are.
The issue, to me, is this idea of viewing "keeping" communities "middle-class" and "nice" through some sort of race/discrimination-agnostic lens, in a country that's historically (within living memory)(of Millennials) done anything but.
Unfortunately, race and racial politics are inextricably linked with housing policy in America. It's impossible to talk about "nice places" without digging into the racialized meaning of "nice", or to talk about "middle-class" places when those encompass everywhere from "shops at Dollar General" areas to "orders Instacart from Whole Foods" areas. And, in terms of "keeping" neighborhood character, it'd be interesting to know the history of the specific neighborhoods you have in mind. "Were they gentrified, or just always inaccessible to marginalized people?" I wonder.
So, sorry, these nebulous harms to "niceness" don't cut it as reasons to forbid development prospective (and, often, current!) residents desire.
>I am not affluent and I have never had an ounce of power to influence anything
I've never met someone who was who'd admit to it. However, giving you the benefit of the doubt: that characterization was not directed solely and expressly at happytoexplain.