I'm not sure that a violent woman is a strong one. There was a time when women were smarter than men, and were the calming influence on we less evolved. Now, women want to be the ones bashing brains in, and the "men" are attracted to the most manly women.
I find this strange.
The only answer that makes sense to me is that these movies are actually driving culture to be more accepting to behaviors previously thought to be abnormal and undesirable. I guess it's because I don't watch them that I'm still more interested in brains than brawn, when it comes to women.