(On reading a book to understand a simple principle)
You obviously don't get it. You can't expect someone who uses the % operator to have read a book on number theory first. Therefore it should behave intuitively and comply with what the commonly accepted understanding of the term is, so long as it is sensible and consistent. I think I have demonstrated in other posts that a modulus of 0 is neither sensible nor consistent, except with one contrived definition of modulus which I still think is bogus.
You say a modulus is defined one way; I say another. Who is to say who is right, or whether being "right" means anything? Let's end this rant and agree to disagree.