Miles Davis,extreme Jazz and the death of Jazz

Having re-read through the excellent recommended Jazz recordings thread on this forum I was struck by Sd Campbell's comments on the lack of invention in modern jazz.
Don't take any of these comments the wrong way as I am no great historian on Jazz but this is merely my impressions....
Miles D was a constantly changing stylist in Jazz and although obviously the cultural impact of popular music(rock n'roll whatever)had a big impact on the popularity and possibly even the development of jazz however was it Miles adventurous spirit and anti-status quo stance not to mention his embracing of rock musicians that ultimately left Jazz nowhere to go?
I really love the Bitches Brew era but then I'm mainly a rock fan but did this album signal the end of Jazz ?
I am interested to hear from the Jazz scholars on this forum about the more extreme variants of Jazz and their views on it,be it free Jazz or Miles later output.
Has there been a great Jazz innovator since Miles?