Why do questions that involve issues between men and women always draw so much response and get people so worked up?

Do you notice how questions that involve issues between the sexes always seem to draw a lot of responses, and often results in long and heated debates? Why do people get so touchy and involved about the subject, about men vs. women, women vs. men? Are men and women so vastly different that we have to debate about it so fervently? It suggests to me that there is a lot of repressed dissatisfaction and frustration out there.