That Keith Richards solo on "Sympathy" does indeed fit perfectly in the song and that harsh tone on it was just...well...perfect.
As far as players who can play real fast, etc. I guess that it doesn't seem all that impressive next to Eddie and others who are so technically skilled.
But for being a part of communicating the idea of the song...yep, it's one of the best.
And actually communicating an idea with an instrument can be conceptually a lot more difficult than just wiggling your fingers as fast as you can on a piece of wood with 6 strings.
But like DynaMo said...it's definitely NOT a "one note solo".
I read an interview with Eric Clapton in Guitar Player many, many years ago where he talked about the "less is more" theory. He said he has been searching his whole life to be able to play a 1 note solo and have it mean something.