Much (though certainly not all) of what scholars have found questionable in the authors you mentioned is not that they don't "fit into present categories of knowledge," but the opposite: they can
always be fit into present categories of knowledge, no matter what. When Freud says that women secretly desire to have penises, for example, any woman can either affirm this, in which Freud is correct, or deny it, in which case Freud can play the repression card and still claim to be correct. Theories of the unconscious are often built on claims that can never be wrong, and therein lies their weakness. If the results of repression and the results of non-repression are indistinguishable from each other, then applying either term is an entirely arbitrary exercise. This is not to say that there's no such thing as the unconscious or repression (beats the hell out of me whether they exist or not) but their existence or non-existence doesn't actually change anything because they are always applied after the fact, and there's nothing stopping the determined psychoanalyst from applying them to anything. As such, they are not explanations about "why we do the things we do"; they are labels we give to why we did the things we did. I readily acknowledge the importance of labeling, but labeling is different from explaining.