The problem is that the goalposts for what is unacceptable are constantly moving. The extremes and most emotionally invested are deciding what is is racist/homo/transphobic/etc for the masses. Once you cross that line, you are lumped in with the worst racists in human history. Even questioning those standards, or laying any criticism towards activist groups, is seen as an act of racism and aggression.
For example, I have no problem with Central Park Karen or someone dropping in N bomb in public getting shamed and dealing with the social consequences. However demanding that someone get fired because they tweet "all lives matter", or because their photo is taken with their fingers hanging out of a truck window that vaguely resembles the ok sign (which is now the white power symbol), is absurd.