A few of my best friends are women, but all of them are also dating other friends of mine. I've definitely noticed that unless a girl has a boyfriend, they seem to generally think we need to become romantically involved, which is super annoying. So far, my solution has been to maintain emotional distance with pretty much any and all female acquaintances.
I think most people tend to think that they need to be paired up, so the natural tendency is to gravitate toward relationships, even if they're obviously a bad idea. Our species is a lonely-feeling one.