Don't shoot me out of the water over this.
Just ask any management pilot how much grief SOME female pilot's cause them. Not in terms of their performance but more to do with maternity leave, baby sitter problems, PMT etc.
I do not want to project a disciminatory tone here, as many female pilot's are very good, as we know. The cost of the above problems, according to some management pilot's is not worth the hassle.
There are of course plenty of useless male pilot's who do not deserve to be in a job such as ours. The system unfortunately allows these idiots to get through from time to time.
Some intellectual debate is warranted in this area!