Kiwi has her suspicions:
IMO, there are fewer women musicians, SF writers, programmers, and many other things for the same reason women aren’t as good at video games: Women tend to spend less time immersing themselves in a pastime, so they’re less likely to be experts. They’re also less likely to care.
During my brief, but glorious time in the music industry, a lot of the girls I knew were bitterly disappointed to discover that the musicians they thought were these incredibly cool demigods were, once you got past the stage glamour, basically geeks.
And this is true of almost all of them, even the wild ones. About the only exception is the bassists, who tend to be the good musicians’ cool friend that everyone wants in the band, so they figure they can teach him as it goes along.
The reason is pretty simple. The music business requires you to be good-looking and to have plenty of free time, so youth is a big advantage. In order to develop sufficient skill at an instrument or to master the programming of their electronic counterparts, an individual has to have spent a lot of time messing around in his basement during his teens.
So, in most cases, the wildly hedonistic behavior of the rock star is simply a geek making up for lost time.