I think you missed the point. Why are entertainers, i.e. musicians, actors and athletes, given all this special recognition? We don't have such ceremony for health care providers, pizza delivery, or food service workers. Entertainment is just a job like any other.
Although I think some of his roles were overlooked and he should have won more, he has won 2 Oscars. One was as Best Supporting Actor in Glory & One as Best Actor in Training Day. I can't say that he has been purposefully snubbed by his peers because I don't have a clue about it.
Denzel's amazing and deserving of many accolades but the year he won Best Actor for "Training Day," I actually thought Russell Crowe was robbed and should have won for "A Beautiful Mind."
Maybe for the same reason Bill Murray, Tom Cruise, Sir Ian McKellen, Michelle Pfeiffer, Johnny Depp, Brat Pitt and Glenn Close have never won one ... "whatever that is!!"