Fortunately there's a big gap between "College kids" and "Kids", and by the time you're in college it's not just about having fun anymore. Sports in college, whether we like it or not, are a large source of upward mobility for a lot of people, sometimes whole families and communities. College sports can determine access to college through the system of scholarships, and of course they can lead directly to pro careers.

Generally speaking when people talk about "kids sports" they specifically mean pre-collegiate, not in the least because colloquialism aside, college students are adults.