You’re not wrong they don’t do that much, but it would be really nice if these critiques could actually inform people who do praxis. There are real errors our movements which they identify.
If you read the important Marxist literature too and engage in reality they are correct that their critiques hold up better than others.
For example, the usual ultra left “not real socialism” circlejerk is surpassed by the criticizing the content of people’s words and actions instead of holding them up to an ideal standard. I found their articles on antifascist liberal collaboration unusually hard hitting.
Their critiques attract superfans for a reason, they just ought to be better taken up. You can understand it much faster than the usual “reinventions.” Also much better than piles of Hegel or historical minutiae defending Stalin.