"Most people wouldn't condemn a man for choosing to talk to the more attractive of two girls at a bar. It would be considered normal behavior. Yet most would condemn a woman for talking to the richer of two guys."
Would they? Maybe I've just been hanging out with too many women (in a non-sexual context), but they complain about guys that talk to the obviously-prettier girl at the bar all the time. Meanwhile, talking to the more successful-looking of two guys is pretty normal, as long as you aren't blatant about it (eg. asking how much they make).
I think it's more that girls will judge guys for going solely for attractive girls, and guys will judge girls for going for richer guys. Both sexes are shallow, both sexes complain about shallowness in the opposite sex, and most people of both sexes will recognize that basically everyone is shallow - in private. But public discourse tends to feature more males, so we hear more about how golddiggers are evil than about how babewatchers are evil. Either that, or it's just because we're male and girls tend not to share their real opinions for fear of offending us.