Of course, you need a theory to explain why universal health care is good or why juking up the public share of GDP would be a desirable goal. I agree with the narrative that says the reason why theory breaks out in such a virulent way, like a cholera epidemic, after the '60s is that the revolution didn't pan out - in the U.S., France or elsewhere - and the left was rolled back. Looking at it dialectically, it's loss and gain. There's been displacement and a deepening of understanding.
My tombstone shall read either "He partied through the pain" or "Had all the right enemies" or else have some bawdy doggerel or else I'll transfer my brain to a clone husk and ponder theory forever.
peace out, Peter