When I write “it’s not representative”, I am hoping to communicate an opinion and not hoping to refute a specific claim you made.

I appreciate unorthodox explanations, and I like to collect them—but sometimes the explanation just doesn’t “land” and in this case the explanation landed especially poorly for me, and I also identified some errors, like the claim that “si” is not in the kana, or that hanasimasu is incorrect—I know that you don’t accept my viewpoint that this is incorrect—sometimes it happens that explaining your point of view or reasoning in more detail doesn’t result in agreement.

What is certainly true about linguists is that they do not present explanations in ways that are consistent with each other—and sometimes not even self-consistent, but they are upfront about the tradeoffs (they present theories and acknowledge that the theories contain errors) and they decompose what they present into different topics like phonology and morphology.

I have read some linguistic texts on Japanese (not very well! It’s a difficult subject). What I saw is a lot of variation.

I think it’s fine that your explanation is good enough for you—that’s exactly what you expect when people make individual breakthroughs in understanding when learning a subject. Sometimes those breakthroughs do not translate well to other people or translate well to lessons and that is the main gist of what I am trying to articulate.