The author is arguing that the rise of K-s is killing true debate (where anything can be advocated for and one wins based on the quality of arguments) with something else (clever appeal to authority and personal attacks).
The aim of debate is to foster people who form their own opinions, but the current structure instead fosters people who blithely subscribe to the current social norms. Critical theory is not revolutionary. Socially, it is dominant (particularly among that demographic). It is actually truly revolutionary to disagree with it, e.g., take the stance that capitalism is an effective way of organizing labour.
I also think a white elephant in the room, is that a) a lot of critical theory is incredibly badly reasoned / detached from reality and b) a significant amount of the use of it is done in bad faith (e.g., for virtue signalling, and to shoot others down, invalidate others rather than engage with their arguments and views)