I couldn't agree more. One of the founding principles of postmodernism is that cooption of the language is cooption of power. That is one reason for its concentration in such former intellectual backwaters as literary criticism. It was a lot of earnest people believing with all their hearts that if only everyone pretended that the emperor had new clothing on, he really did. The power of the collective here was the power to create its own reality. It doesn't really, of course. Half of the Left still believes that it does and the other half is mortally resentful that it doesn't. For which we non-believers are to blame, naturally.
Great point! I'd never thought of it that way. In other words, criticism went from being a sort of meditation on a literary text to a thing unto itself, unleashed and eventually becoming more important than the original text.
Probably some of the initiators of this (I.A. Richards, for example) didn't really have this in mind, but because the fundamental nature of Communism/leftist thought is ahistorical, their theory enabled literary criticism to could become a vehicle for any bizarre interpretation, reinterpretation or radical rip-off that the left wished to impose upon a particular work or even a particular phrase.