Women, who have dominated the position of pop singer, have often been devalued through a construction of femininity as an unskilled, and/or "natural musical position. Part of this creative disfunction between men and women has a history not only within music (both classical and popular) but within the visual arts and literature.
There's a lot of truth is this. Breaking it down in terms that's easier to understand, there's a certain "nerdiness" to being a musicians. It's implied that being a good technician is mathematical, not passionate. According to stereotype, bands like Rush, noted for their technical skill are the domain of really, really smart guys who sit in their parents basement playing dungeons and dragons. (When they're not listening to Rush, of course.)
Passion defies logic. Technical proficiency isn't required if one is passionate enough about one's art. This is a good thing. Punk couldn't have happened if, well, if The Ramones knew a few more chords. But as men are allowed to be passionate or skilled (or both), women are only noted for their passion. A well-respected rock critic recently published a book that, in no certain terms, women, as fans, aren't supposed to be "logical." They just want to dance. Granted, there is nothing wrong with dancing, but that kind of gender essentialism makes me uncomfortable. Even though we're talking about pop music, it still takes women out of the intellectual sphere, and takes away their sense of agency. (The music controls me. I don't make it.)
I am not a musician. I can't speak about the act of making music with any authority whatsoever, but I was an art major for a few short seconds, and you know what? Being an artist in whatever media is a lot of work.