In my earlier thread I talked about how speed is very important to being a virtuoso---to mixed response. Regardless, something that everyone can agree on is that to be a great player, you have to have uncanny control over the instrument.
This is not necessarily with regard to technique in the traditional sense---as in, you can play ascending 16ths at 210 on acoustic to perfection.
This is probably, in my opinion, the real 'musician' aspect of playing rock music and why some rock guitarists who don't appear to have spectacular chops are revered---control.
The volume at which you play lead in rock music forces you to employ techniques for muting the strings at all times. And the degree to which you can do so can greatly influence your success as a rock guitarist.
A good example of a great guitar player falling flat on his face when attempting to cop rock is Eddie Hazel on Maggot Brain. Everyone gives him mad props on the solo, but to be honest, if you or me went out on stage in a funk-rock outfit and played that---the band wouldn't be too impressed. It's not because of the note choices, speed, etc.---it's because Hazel fails to control the volume and power of the rock guitar.
Another, more common, example is the fact that so few people can play 'Highway to Hell' correctly. Most just hit the open A, hit the Dsus2/F# and Gsus2, others palm the chords as they hit them. Very few actually hit the chords with a slight fraction of palm muting, then cut them short of the slightest ring.
If it's a lick that requires deft muting then look no further than Red House by Jimi Hendrix--the one that he plays just as the progression goes to the IV chord. The fingering for the way he plays it requires advanced control of the guitar, especially for that speed. Notice also that he is not palm muting the entire lick--just the small bit that needs it.
The point of this entire thing being to listen to yourself when you play---and not just the notes. All the little tiny clicks, burps, and whistles. You could either try to avoid them to come out with an ultra pristine style--Yngwie---or you could just add them in with skill--Slash and EVH among others.
Back In Black isn't a song. It's a divine call that gets channeled through five righteous dudes every thousand years or so. That's why dragons and sea monsters don't exist anymore.