Quote
we told them it was not about being with your friends. You don't need to be friends with the other kids on the chess team, math team, baseball team, etc. You just need to be polite and respectful, and be a teammate.

It's not about being with your friends? What IS "it" about? Unstoppable pursuit of excellence? Man, these are kids. I can't blame my children if they don't want to continue in an activity where they have no friends or are treated poorly by other kids, even if they're good at it and enjoy the activities. They aren't robots. I mean, if they want to continue anyway, of course, more power to them, but not enjoying the social aspect of an activity (especially one with a heavy time commitment) is a valid concern, IMO.

FWIW, research on what kids like about sports show that what they value most about it are being with friends and having fun, with skill development also on the list. Winning and getting trophies ranked very low.