i think this is a great question, one with contradictory tendencies (not that i have a weakness for that sort of thing!).
on the one hand, the concept is a favored tool of essentialists and reductive thinkers and mind fuckers in general. "you don't know what is good for you, you don't know what you really think". i have definitely encountered this accusation (ie the concept of false consciousness in its most boring and superficial form) from identity politicians.
related to this is the tacit (?) assumption that there is a true consciousness, which i disagree with on general principles.
on the other hand, i agree that -- based on what we're taught by the status quo (system? our enemies? leviathan? etc?) -- we all (perhaps to varying degrees) do things against our own best interests (occasionally, frequently, or all the time)... and even against what we believe, and want, and would do if we had more time or a slightly different perspective. does it make sense to call that "false consciousness"? i don't know. sometimes?
those are my thoughts atm.