Speaking as a Damn Feminist...

...but not a damned feminist, you'll note. Important distinction to draw.

So anyway, as a feminist, I'm pretty confident to say that I speak for all women who agree with me on this next thing I have to say, which is this:

The insulting part of calling a man a "bitch" has as much to do with the word's feminine aspect as the insulting part of calling a woman a "bitch" has to do with its canine aspect. Which is to say: NOTHING. It has nothing to do with it. When you call someone a bitch, you're not calling a man a woman any more than you're calling a woman a dog. The insult has long since moved on from its ancient etymological roots, okay? It has subsumed its referent, and is now linguistically sufficient unto itself.

What's insulting is that you're being called a bitch. That ought to be quite enough for you.

Or to put it more to the point: that ought to be quite enough for you bitches.