One can be falsely accused of many crimes, not just rape. Every case of (knowingly) false accusation is heinous and despicable.

The women (self-identified feminists and otherwise) I've spoken to about the problem of false rape accusations have basically the same thing to say--"oh, boo hoo, men have it so hard, that's nothing compared to being raped, etc., etc." But if we campaigned for harsh punishments for any knowingly false accusation, it is no longer a gender issue in the eyes of detractors. And it would still be an important change, because, seriously, trying to send people to jail for shit they didn't do is always fucked up.