Complaints of all kind probably go unheard because Varsity knows they're the only game in town. Of course sexual predators wouldn't "just go away", but that's not a reasonable expectation to have, but it is reasonable to expect companies to not ignore such complaints. Without a monopoly, for example, you can apply pressure on Varsity to do something about complaints by going with Nike next time or by getting Nike to do something about it.

I think the article does a good job of explaining this...

If the governing body is beholden to a company, then the company's priorities (money) will be what the they care about. Which I think is what happened here.

I think that it’s likely that a field which wasn't a monopoly would more rapidly evolve better systems for dealing with reports than a monopoly, in part because the discussions between participants on the other side and the industry would be more likely to be open discussions about industry-wide arrangements rather than confidential one-on-one negotiations, and in part because failing to deal with them would be a potential short-term competitive benefit (avoiding a narrow scandal) that would have long-term competitive adverse consequences (the greater scandal of more abuse plus neglect and coverup.)

But without competition, the pressure to deal with problems is less, until the consequences become existential even in the absence of competition, which requires them to get extremely bad (cf, USA Gymnastics.)