agittayid:
You are correct it comes up often. Yet in almost every instance it is brought up by folks who begrudge those who do wear a black hat. Just look at this very thread for example. The OP was not content or comfortable that he himself doesn’t wear a black hat; so he had to question and be dismissive of why should others wear them!
So, yes, you are correct about it being unbecoming. Though that attitude and discomfort is coming from the headgear-less.