My son tried out for football a couple of years ago and had a horrible experience that I believe (along with other factors) contributed to some severe depression and social anxiety that he is barely recovering from right now.
Another son had a great experience a few years ago listening to a missionary fireside where an elite college football player talked about his experiences being recruited to the likes of Alabama and turning it down to be a missionary instead. So I admit that it isn't all bad.
But my bet is that your nephew's experience is more common than not, even in Utah. And if I had to choose a high school sport for my kids to participate in, I think football would be pretty near the bottom of the list.