Yeah, I think the issue is a casual/familiarity vs. professional/formal situation distinction more than a politically correct one. Dude/chick make sense in casual situations where one has some familiarity relationship with the other person. They aren't often terms one would use in a formal or professional relationship.

I suppose the interesting question to ask is does HN think of itself as more of a professional/formal discussion community than one that leans towards casual/familiar?

(I'd assume that the answer is that it probably varies with comment writer and both sides of the argument are represented here and have fair points.)