Kurt Cobain, who Rolling Stone Magazine ranked as the 12th greatest guitar player of all time, teaches you the value of music theory in this rare video (at 1m50s):
“I have no concept of knowing how to be a musician at all, whatsoever. I mean, I don’t know the names of chords to play. I don’t know how to do major and minor chords on a guitar at all. I couldn’t even pass Guitar 101. Folk Guitar 101. Everyone knows more than I do. …I never learned how to read the music. I just copied the other people that took the time to learn how to read… [Dave interjects, “He’s a good drummer.”] …if you go by a text you’re pretty limited, you know.”
“[I’m a] songwriter. I have no desire to become any better of a guitar player. I’m not into
musicianship at all. I don’t have any respect for it, I just hate it. To learn how to read music or to understand arpeggios and Dorian modes. It’s just a waste of time. It gets in the way of originality.”
So, if you are one of the many, many guitarists who think technical proficiency makes you a good musician, then that ostensibly means you and I are probably both better musicians than Kurt Cobain. Except, probably not. So forget music theory. You can have fun sitting in your room practicing your stupid rock solos which all only use the same scales anyway, but the audience doesn’t care how good a guitarist you are. They can’t even tell when you suck. All they know is whether or not it makes them feel something. That’s all that matters.