The most pointless arguments we can possibly have are; "What is jazz, or what is not jazz". That's right up there with what is or is not "Blues"; this is determined by the current majority; I'm reminded of "The Beatles"; "Let it Be".
What we hear is determined by the same factors as what the musician plays musically. The musicians origination is one of the greatest factors in what he plays. What he is actually playing, and what he thinks he's playing might be two different things, but words are one thing, and music is another, and words, not music is what's in the books.
I have a number of music encyclopedias, and the musicians that are labeled as "jazz musicians" is astounding; it seems that the most current books are the most different in regard to what the musician is playing and what I hear, but in this case, definition is determined by younger people for younger musicians; whatever it states is what is, like it or not.
I must not forget that when a record is played, we hear differently; what sounds good to a much younger person may not be so agreeable to me. I'll give you a better example.
Since I knew some of Miles Davis's close friends and relatives; although they would never say it in public, but only in casual conversation with someone they confided in, they could live without Miles most current music. When you think of how many times Miles changed over the years, and how many generations have come to like his music, it's not hard to understand how those who based their collection on what was best during the 50's and 60's, might not have been too fond of his last music, although they didn't love Miles one bit less than when they grew up together.
We have to agree, to disagree, and "Let it be".