the almost insurmountable combination of conditioning and coercion

The hegemony of the ruling class, in other words. I agree.

It depends how you look at it, though. Did those pressures stop a kind of subterranean oppositional working-class consciousness expressing itself - or did they stop it developing in the first place? If it's the latter, we may have to accept that folk radicalism is a modern phenomenon, and the old songs come out of a tradition that was never - or only very rarely - at all radical.