Why would they spend time directly thinking about practice if the core of their theory is that real practice isn't possible right now? I get it, you clearly disagree. But you shouldn't frame that disagreement as if it were counter to their theory and puzzling. It makes perfect sense if you buy into what they are selling. Also, it isn't that simple, they do think there is practical activity you can do. You write messages in a bottle, theory & culture, that aren't instrumentally tied to direct action, so as to prepare ourselves for the day when direct action is actually possible and practical. Some moments in history call for 'holding the line', and some moments in history call for direct action. Adorno was hard on the hippies and hard on the Soviets. But Marx also didn't just jump at every revolutionary who knocked on his door for help in jumpstarting history, and there were a few. You make judgement calls. Because you disagree with the judgement call doesn't mean they weren't committed socialists.