Why isn't it socially acceptable to state that looks are important? I feel like people are conflating "external appearance matters" and "external appearance is all that matters" and demonizing the former in their attempt to ward away the latter.

Huh.

I know that I'm probably unusual. I really haven't ever cared much about looks. I've mostly valued intelligence, good sense of humor, interest in sex, independence and (frankly) a credible career.

And in retrospect, among my former wives and lovers, it seems like the less conventionally attractive ones have aged the best.

This is not strictly true, its just exceedingly rare.