I did a Google for "munter slang" (no quotes) (because just "munter" got me a lot of information about dehumidifiers) and discovered that a "munter" in this context means an incredibly ugly woman.

Yes, it's derogatory.

I have to agree with the decision. It's arrogant as hell to assume that if you don't find a woman attractive that therefore she cannot be found attractive, and yeah, I'm probably talking to the majority of... Americans, anyway, and probably more. Whose tastes are definitive, anyway? Not mine. But the difference is that if I find a woman unattractive I don't insist that she's ugly. At most I'll say "she's not to my taste" or "I don't find her attractive." That's what's called "an opinion." Calling somebody ugly is a judgement, and I'll call you on it.

And we've been talking about women, but of course it applies to everybody.

OK, sorry for the rant. I've got more, but now isn't the time. :) My point? He could have expressed himself without being an asshole about it. But nooooo, he had to be insulting and derogatory, rude and disrespectful. I have no sympathy for his position.