Whenever you criticize authoritarianism as practiced by groups or individuals that position themselves on the left, at least one person shows up to invalidate your criticism, without really engaging with what you brought up, and that not by mere logical reasoning, but by applying an ideological believe that thrives for some sort of unity, and just pushes that believe with what ever logical fallacy suits at the moment best.

I don’t get it. What’s the problem with criticism against authoritarianism in an anarchist forum?