I'm not sure I agree with this, after skimming the paper. For instance, the author does not seem to be using terms like quantum factorization in the usual way (In the sense of a problem tackled by Shor's algorithm).
I've only glanced at the paper, but it looks to me as if he's using it in another perfectly usual way, namely referring to situations where the wavefunction and/or the Hilbert space it lives in can be written exactly or approximately as a product over simpler things. There's nothing wrong with that.