My own experience is that I couldn't care less about my property value: I view my mortgage as mostly a locked-in monthly payment, a guard against rent increases and against being forced to move if the landlord decides to do something different.
However, I would actively campaign against a large multi-family housing development being built within a few blocks of me. I don't want the added traffic it would bring, I don't want the added noise, and I don't want the more frequent turnover. I enjoy being able to recognize all of my neighbors, not just because it's nice but because it makes me feel safer.
If you actually went out and interviewed NIMBYs instead of just reading the stereotypes on the internet, I suspect that the motivations I describe above are much more common than wealth. It's not as exciting or provocative as "the upper-middle class just wants to get richer", but it's the reality that many of us live in.
