Can't say I'm a fan of this sterile world where realms of human experience and observation are ignored for the sake of an ideology.
What realms of human experience and observation are we ignoring? I suggest the opposite: Slurs like "bitch" are lazy, they ignore the myriad of subtle colours and shades of human behavior and replace them with a catch-all that means roughly "we disapprove of you."
I am certain that a man can damn his ex with far more wounding intent by expanding his vocabulary and unleashing his inner poet. Such insults would hardly be sterile, they would be fecund.
Back on topic, the ideology I was thinking of is the idea that men and women aren't statistically different (or if they are, that mentioning such things is impolite). I would argue that "bitch" captures a characteristically female way of hurting a man with whom she's had a relationship. (See Carmen for the high-culture version, or Louis CK for the pop-culture version - http://www.youtube.com/watch?v=ZpW3orlfp7E) It's true that the word also carries other connotations, but I don't think that was the intent.
I agree that it may be "lazy", but from a purely practical perspective, it would be tough to find a similarly short word (short enough to fit on the bobble-head) that conveys the meaning. "Evil" might work and is gender-neutral, but the class of actions that make one "evil" are broader than the class that make one a "bitch".
Somehow we got sidetracked onto the issue of whether it's ever ok to use a gendered description of someone's bad behavior.