Well, I think it comes down to this:
Humanity is in the imperfections. Also, vibrato is a technique thats largely up to the individual player. Nobody has quite the same vibrato. I think that bends and vibrato are more expressive than a barage of fast notes. You can make your guitar wail, moan, cry, whatever without changing strings. It's all in the fingers. If you're playing fast though, it becomes increasinly difficult to add vibrato or bends- you basicly have to stop to add it. But, realy fast notes played the right way are excellant for building tension and/or intensity in a solo. Nun Chuka Kata by Buckethead comes to mind. That's the one example of shred that I can think of that really moves me; their's this one spot where he takes the guitar someplace "higher." Then again, I don't listen to much shred, so I don't have the background to give more examples.
I can also see this in my own playing. I can throw out some ungodly fast funk bass that's impressive, but you won't find anybody dancing to it. A simple groove on the other hand...
The bottom line here is that everything has it's place, everything is related, and everything can be mutilated to work anywhere. But when it comes right down to it, some guy shaking the piss out of his B string sais a lot more to me than flawless appegros.