Yeah, I've never liked expressions like that, either. "Man up," "be a man"... Then there are all the ones associating testicles with courage, boldness, etc... I've never used these phrases even once in my life, and they always make me feel uncomfortable when I hear them. Then, of course, there are the ones like calling men who are perceived to be weak in some way a certain slang word for female genitalia...
It's all pretty uncomfortable for me to hear...