A chauvinist is someone who thinks he is better than others. Most often, this is a man who thinks he is better than women. The women that Wufei seems to disrespect are the ones who are the ambitious ones whose ambitions are greater than their abilities, such as Meilan and Noin, both of whom challenged Wufei and lost. It's not exactly women in general that Wufei doesn't like, it's the "obnoxious" (for lack of a better word) women that he doesn't like.
Throughout the manga/show, we see that Wufei doesn't like obnoxious people in general, such as those who run wild when they are given arms. My humble hypothesis is that Wufei dislikes obnoxious people and he dislikes obnoxious women even more. This is not difficult to understand when one considers the fact that Wufei is a scholar and scholars are more of the silent-type. Obnoxious people tend to disrupt their thoughts.
It is also obvious that Wufei has little patience for those who don't fight as well as he does or who aren't as smart as he is. This is simply because Wufei is, before anything else, a seeker of knowledge. While he searches for the knowledge and the truth, it becomes frustrating when there are those around him who pull him down more than help him along his quest. When Wufei scoffs at those less gifted than himself, what he is essentially saying is,"I don't have time to deal with you," which is something that you have all at some point thought as well.