Hm... so to clarify your position, would you call, say, Saul Alinsky a destructive rent-seeker in some sense? Hayden? Chomsky? All high-status among the U.S. "New Left" (which you presumably - ahem - don't have much patience for) - yet after reading quite a bit on all three, they strike me as reasonable people, responsible about what they preached.
(Yes, yes, of course I get that the main thurst of your argument is about tenured academics. But what you make of these cases - activists who think they're doing some rigorous social thinking on the side - is quite interesting to me.)
If it's worth saying, but not worth its own post, even in Discussion, it goes here.