learsfool, you are a classical musician. You think and speak like a classical musician. By now you should realize that "all" musicians don't even live in the same world, even when they only live blocks apart.
I'm sure the jazz musicians I knew had to learn their skills somewhere, but they did not practice. As often as they performed, they didn't need to. Yes the kind of musician I knew was rare, but I have no reason to fabricate.
Your world as a musician, is so different from the the jazz world, that you're having a hard time accepting it. You stated that all the musicians you knew were into the high end. Now I know why, "Classical music sounds like noise when it's played on less than high end equipment", but that's another subject. According to Branford Marsalis, he was the only jazz musician he knew who was into the high end. John Lee Hooker had several homes before his death, and he had Kenwood rack systems in all of them, he said he liked a "funky" sound. Musicians I knew were either working on a gig, or digging a set, and rarely sat down to listen to recorded music; of course we were both young then.
Wynton Marsalis could be one of the most perfect "Classical" trumpets ever as a result of all the things you have stated about musicians, and he could be the best "side man" ever. If you call that "Wynton bashing", so be it; but I'm using him as an example of what you think the most accomplished musicians have to be.
Erroll Garner was self taught and remained what's called an ear player. Learsfool, you are imposing your reality on a world that's foreign to you. We all do that at times.
Enjoy the music.