Playing sports is just good all around. Sure it'll help foster that "winning attitude," but it'll also help you w/ hand-eye coordination (some sports more than others), maybe you need to learn to work on a team better, whatever. But college sports is a different animal. I played intramural stuff and just pick up games for fun, but didn't play actual NCAA sports or something. It's very hard to do school, ROTC and play a Div I/II sport. If you can do it, more power to you, but very few are able to. Back when I started college, I may have been able to play baseball had I stuck w/ it, but it was going to be way too much to play baseball, get a degree, do ROTC and still have time to do the outdoor stuff I loved to do. While I like baseball, the time commitment just wasn't worth it to me...I went to college/did ROTC so I could get a commission and fly, that was my main goal, so I did what I thought was best to help that goal along.
BL: If you're thinking playing a college sport is somehow going to drastically help you become a fighter pilot, it's not. Skills and mindsets that make a good player and a fighter pilot down the line (referring to the dudes in your book) were most likely developed before playing a college sport. When it comes to flying, you either have the drive or you don't, you either have the hands or you don't...whether you played football in college has little if nothing to do w/ UPT or flying in general (w/ the small exception if you had no drive and football gave it to you or something...but that's a little out there).