Western exceptionalism + discovering new political views is a hell of a drug (side effects may include arrogance, smug demeanor, and believing you've invented views no one ever thought of before).
The most humbling for me was the first time I read theory. Because it was this eye-opening moment of like "oh, there are people who have already been over this stuff to an incredibly detailed degree and put it into practice too".
The straight up erasure of scientific socialism in the consciousness of the capitalist west is real. Even among people who are supposedly on that side, you can tell that some of them are just kind of stating the views they think are the correct ones without understanding why communists arrived at those views, historically. And it's not that I think everybody should be prepared to write a dissertation in defense of communism (in other words, my mind is not in the realm of some kind of "true communist" elitist gatekeeping). But it's sort of like the difference between cooking a meal from a recipe and knowing why the ingredients pair well together. If you have the second, you can make your own variations on the meal confidently. If all you have is the first, you'll have a hard time adapting to changing conditions. Mind you, this is not something you just "learn" as a single thing and now you're an expert. I think it is something that tends to come from prolonged combination of theory and practice, and many of us are in varying stages of working on it over time. But here is where a major problem is for the pundit style of "leftist"; if they never do the practice, they become mired in spinning their wheels on theory only.
Some of the pundit types I'm sure are just opportunists though and it's not even that complex as to how they arrive where they do. They arrive at it because it's convenient and it secures them a living in the capitalist world; they can exist on the edges as a reformist, without drawing the violence of the state upon them.