So you see a guy that can pull 100 nps or whatever is considered fast and odds are that's all he can do. That tempo only applies to certain styles. You ask that guy to play over some other style, other than what he's used to whipping the solos ontop of, and he's lost (brings to mind a thrasher I played with in a production of Grease hahahaha). A decent guitarist is well versatiled which stems from being a musician. That's why the people at the top are at the top - speed counts but it's only one aspect. And sure you can get away with no theory whatsoever but you've got to acknowledge that it's only going to be a limitation. SRV and Hendrix could not have gone out of their realm because they had no theory. They were very good at what they did but I'll bet you they had regrets (actually 1970 Hendrix started looking into learning theory before he bought it - for orchestral reasons I think, I can't remember). ... A good ear, in my opinion, is unrelated with theory. A good ear come from experience, learned in time. By a good ear I don't necessarily mean pitch-wise, but general musicianship-wise.