Very well said. It's really about the complete package. Real life example - I saw Kenny Wayne Shepherd for the first time as part of the Experience Hendrix tour. He absolutely killed it. I walked away thinking that this kid was the next SRV. Fast forward a handful of years, I saw KWS headlining. Phenomenal guitar playing, but his songs sucked. I mean BAD. The only time the crowd went nuts was when he played Hendrix or SRV covers. Dylan (and for that matter, Hendrix) did not have great singing voices, but the total package (delivery, lyrics, musical ability, etc.) made them great.
And I love me some G-n-R, but I can't stomach their version of Knockin' on Heaven's Door. It is terrible. (Although, I love their version of Live and Let Die)