The cynic in me says these Holocaust denial people are Morris Dees-type creations. Good for fund raising and a way to stop certain unpleasant facts about the activities in the Soviet Block from being taken seriously. Follow the PC line on 20th century history or be lumped in with Holocaust denial nutcases.
But I don't listen to my cynical side. I'll accept that these crazies are for real. But they sure come in handy.
Obviously, Holocaust denial and Holocaust deniers are real. The denial of that fact is a form of Holocaust denial in and of itself.