There are some professions that provide opportunities for perverts. Coaching is one of them. It’s why the Boy Scouts are fighting to maintain the integrity of its leaders.
I would not be surprised if you find at least one pervert on every coaching staff from the pros right down to the little leagues. I remember more than one sadist, and at least one sexual pervert on coaching staffs when I was in school.
They get away with it because we take sports way too seriously.
At my HS there were at least two lesbian and one gay coaches. The girls volleyball coach was briefly my homeroom teacher. She used to "hold court" before school with her favorite girls. They would sit on her lap and she would kiss and fondle them. (Don't bother with the fantasies...this coach looked like Danny DeVito in drag.) God knows what happened elsewhere. It was all out in open, everybody knew about it. I imagine it is much the same in thousands of schools.