But such an outcast ceases to be sympathetic the instant s/he makes someone else's life unpleasant. This isn't about "man hate"; this is about someone who made an offensive comment that made someone else uncomfortable. That's not OK, and we reasonably expect better socialization in our peers than this. If the person who made this remark is not a "happy, mentally-healthy, well-adjusted human being", then no matter how much compassion his condition might reasonably engender, he should get help.
Furthermore, by equating a lack of compassion for a man who is "not healthy" with "man hate", you implicitly claim that "men are naturally unhealthy". To me, this comes across as a greater denigration of men than any harsh reaction leveled at the oppressor.