I've never been athletic at all, and I generally dislike playing sports, but I still appreciate having been encouraged to do little league and basketball when I was a kid. It's not about forcing kids to conform to social norms, it's just ensuring they're well-rounded enough so that they can make their own choices later in life.

My parents sent me to a school where painting, woodworking and handworking (basically knitting, sewing, crocheting) were all mandatory. It pays dividends now because having a background of creativity helps nearly everyone, even plain-jane computer programmers like me. Everyone had to perform in a play every year, no matter how much you didn't want to. That helped build confidence and the ability to speak in front of people. Gym and sports and recess are all important too -- no one regrets having too much hand-eye coordination, or the ability to play a pickup game of basketball without making a fool of oneself later in life. It's great to be able to relate to and be friends with people who are into sports even if you aren't, because the alternative is to politely remove yourself from all those interactions, and that's no fun for anyone.

I really do think that all kids should play team sports. If it's totally obvious that their passion is theater, or computers, or art, or music, or whatever it is, then there's no need to try out for the varsity team in high school, but giving kids diverse experiences and making sure they are physically active and aware of their bodies is never a bad thing.