Funny thing is, fantasy originated as a "boy" genre. And, outside of YA, it still is. And most of it is still sexist and still grounded in the European medieval world.
By sports books, I take it that you mean Tangerine or the Matt Christopher series? I loved those in elementary school, and I was the only person (girl or boy) who read them.
I don't think your generalization works until boys reach a certain age. When I was in school, girls and boys read the same things until puberty. Captain Underpants to Unfortunate Events to Goosebumps to anything you can think of. And that was in a pretty conservative district in Alabama.
And while I like reading about sports and playing sports, I never understood the obsession with sports. Of course, no one, not even I, read Summerland (a book about baseball), and I was the only person who read Crash (a book about track and football). I think it varies from person to person. And, once again, culture. If not, why do more girls tend to gravitate towards "boy" things than vice-versa? It's socially acceptable for a girl to be a tomboy, but not the other way around. A boy might not like romance, but in America, it's been ingrained into his head since birth that it isn't right for him to like feminine things which are seen as inferior to masculine things. It's always been that way in America. Chick-lit is inferior to dick-lit(Nick Hornby). Chick-lit writers don't get awards like dick-lit writers because romance isn't seen as deep or profound. It's seen as girly, which is synonymous with weak and bad.
I prefer science-fiction and fantasy with a splash of romance and action. But I write contemporary because I'm not a good world builder. I wish more guys would read cross genre though. Goodreads is 70% female, which isn't a problem, but it wouldn't hurt a few guys to read more and join.