Personally the guy might be a little short in the humor department, but his music isn't lacking in it. (Not that there's necessarily anything wrong with humorless music -- I mean, we all love our post-1963 Coltrane, right?)
Blaming him for the stuff that came after him but never matched his creativity is unfair. Are we going to blame Weather Report for smooth jazz, John Coltrane for cookie-cutter disciples, or Horace Silver for the less interesting soul jazz pianists?
At the very least I don't think this characterizes Facing You. (Perhaps you can elaborate on "pseudo-soulful"?)
Are McCoy Tyner, Chick Corea, and Herbie Hancock peripheral to the main thrust of the music?
Look, if you say that Keith Jarrett's recorded too much, or that some of his music is pretentious wank, or that he's overrated in certain (not necessarily jazz) circles, or that some of his fanatic followers are annoying, then I won't disagree with you. But I think your criticisms go beyond that, and I disagree. Furthermore, my superficial understanding is that John's book also goes beyond that. If someone could summarize the passages that deal with Jarrett and post their notes here that would be great...
Guy