simple - it started off with white men using blacks as slaves. so for a long time to come, if not for the rest of eternity, blacks will always be treated this way - having a special day or two for them.
white people try not to make themselves seem like the bad guy again, thus no white pageants, or no white tv, white only schools, etc. blacks would just call them out on the slavery, and these 'white-only' things would be cancelled. it's much like women only gyms - men have beaten women for years, so they, and the government, have no problem with these gyms, yet if a man-only gym was to be erected, women would say they're discriminated against, and because of the years of spousal abuse, would get their way.
that's how the world works, folks.
