Ahhhh, but they can? Now we all know who you are talking about!
Yeah, well, you know girls
can call each other b*tch*s
but guys don't go there.
I explained this on a thread that was subsequently pulled, for reasons that border close to this one; except this has an actual story on which to comment.
The reason the word got used amongst people it targeted was that it helped take away the power from the word. Even the younger generations know the word was used against their parents, and grandparents, by people who had a force to back them up with no recourse. Quite often that force included that of government, or at the least, with government turning its head in silent consent.
It's an attempt to change the meaning and take ownership of the word. It's working, as some people lament that they aren't allowed to say it when its intended targets are.