Here’s one more contribution on the DeFrancis/Ungerian proposal that all writing systems are fundamentally phonographic: Zev Handel, Logography and the classification of writing systems: a response to Unger (2015).
I think we can all agree that the DeFrancis research programme has successfully proved that hànzì and kanji are not ideographic, that they represent language, and that they (also) encode phonological information and are decoded (also) into sounds. The remaining question is largely a matter of emphasis: do we think that this phonographical component is so important and fundamental that hànzì, or even kanji, should be understood as, ultimately, a kind of phonography (and a poor one at that)? Or, is it productive to consider its non-phonographical components important enough so as to classify them as “another kind” of writing (and perhaps not so poor at all)?
Handel above reviews psycho- and neurolinguistic studies, and argues for the latter position.