What do you think happens in football practice tackling drills or a scrimmage or wait for it ... a game? Every hit/block you deliver isn't going to be perfectly set up for you, let you get your feet in the proper position, make sure you're balanced; you're not going to be afforded the luxury of making sure the guy you're going against isn't going to be too much of a strain for you.
I'll guarantee you there isn't a football program across the country (at any level above middle school) worth a darn, that doesn't have power cleans (or some rendition of it: hang cleans, jerks, clean and press, high pulls, etc) as a major part of their work out regimen. This is a non issue, and it's very surprising to me to see this amount of doubts about this exercise which has been a staple of athletic workouts since at least the 80's. And, it's only been more and more confirmed in its benefits over the years.
If you want to question the validity of an exercise, the bench press is the one that should be the object of this witch hunt: very little correlation to actual athletic movements, and highly correlated to shoulder injuries because it causes such a disproportion of front muscles to back muscles.