Because what you are advocating for isn't equality. In an equal world, choices would be made without regard to race, sex, or anything. What you are advocating for is to actively discriminate against white men to even the playing field. Is it immediately even? No. But if you want this to be a fair world it does need time to happen naturally. Let people leave positions and then when those jobs open up, the choice for a replacement can happen regardless of race or gender.
Any push for that to happen that involves discrimination is just as bad as what you are claiming to fight against.
Look at the BBC. Forget about the whole Doctor Who thing. In the past couple years they have been actively firing white men in various positions that were doing just fine at their job just so they can even out diversity quotas.