They dislike Praxis. Really, ALL you need to do is argue with people. If you reach a critical mass of people, capitalism MIGHT fall apart by itself. That's really ALL they believe in (and you can recognize them by this exact enounciation I'm using rn) - so there is literally 0 reason for doing anything beyond posting. Praxis is thus seen as useless at best, damaging at worst.
"Destructive Criticism" is what they call it. Basically everyone who isn't entirely on the GSP line is an enemy, someone to combat and convince, even internally. And the GSP line is always correct.
They'd scorn at this characterization, because it gives them an attribute, instead of examining the exact content (which I do have little specific to say against - I am undoubtedly influenced by my time reading their stuff and listening to the lectures with shitty audio), but it's the cult version of a left communism.