Because some institutions don't want that happening. The Xavier-Cincinnati was a complete debacle and embarrassed both institutions, teams, fanbases etc. The NCAA doesn't take into consideration those factors.
Someone who cold cocks another player like the 'Natti player did shouldn't get one game. That was a brutal of a hit as I've ever seen on a basketball floor.
Do you even know what event I am talking about? Probably a good first question.