Because they have flat out said it. He even gets made fun of by former players for his language.
I get where you're coming from and in most situations in life foul language is pretty unnecessary. My grandmother always taught me it's used when someone doesn't have a proper vocabulary. I love my grandmama.....
In sports, especially high level sports, foul language is literally a part of the game. And let me add, let's end this myth that lots of these college athletes today are "innocent children". Where I coach, the players use worse language than we do. Do you understand what these young men are listening to? Trust me, 80% of them wouldn't understand it any other way.
Like it said, high school, we should hold back somewhat. This level is what it is. And these players aren't Beaver.