I think you can hate self-centered athletes, and still not react like teenager.
I think you can be disgusted that a captain would leave the program, and still not react like a teenager.
I think you can be appalled a player would leave mid-season, and still not react like a teenager.
I think you can hate that a player goes to your rival, and still not react like a teenager.
I think a player could do all those things in one fell swoop, and you still do not need to react like a teenager.
What he did sucks, for lots of reasons. But it's still just football. We move on. Go Cougs.