I used to feel the same way about the personal fouls being too easy to call. However, the long term effects of some of these hits is life changing. I think there are some that are called that shouldn't be, but with the speed of the game, both in the pros and college, it's tough to get it right all the time. Even though it slows the game down, I wish the NFL would review the play and see if a hit did in fact need to be thrown.
As far as the players knowing before they play what the risk is, there are a lot of jobs that people do that have a risk of life and limb. When one of those folks get hurt or killed, do any of us say "well ,they knew the risk!"? I didn't think so.
