Not all leagues are created equal. The NBA is doing a much better job encouraging pride night and cracking down on intolerance and hate in its league than the NHL which is more focused on cramming more ads in your face as if that will return their shrinking and dying fan base.

Yeah, really. There have been virtually no gay players in professional sports. That's simply not in the realm of probability given the statistics of the general population. There are a lot of closeted gay players.

This situation would not be acceptable to the HR department of any other business.

This is a situation that goes to the top too. At any time in the various negotiations with the various player associations the leagues could've had policies more consistent with most companies. Major suspensions (without pay) for players that violate the league's policies on harassment. And yeah being against gay people is harassment, so refusing to put on a pride uniform would fall under that.

The reason this doesn't exist is because the owners don't care about a a real problem of toxic behaviour in their businesses.