Well, like most rules, that one has lots of exceptions (especially if a "diminished" chord is considered "more" than a major chord). Personally if guitarists use just chords (as opposed to melodic runs) as background, I get awfully tired of hearing the same 3 to 5 of them all the time. Is close harmony necessarily "more" than harmony that consists of 3rds and 5ths?

Again, so much depends on the particular song you're playing/singing.