Dave got booted because he was a smackhead...
You need to understand the different between technical ability and musicality. Jimi shredded the shit out of a 69 strat, and sounded music the whole way through through his playing. Dave plays guitars designed to be shreded in a really un musical way. When i listen to stuff like Dragonforce, megadeath, trivium etc. I go 'yeah you can play fast...but i have no interest in listening to you do it'..when i listen to jimi, SRV, neil young (down by the river/cowgirl in the sound (songs that pink flloyd nicked)) etc. i go 'you are insane at guitar and i could listen to you play for hours'. It is impressive to see people play like that, but its not good to listen to.