I think the main pick-up switch offender could be Jeff Beck.
I also like to think John Petrucci's most important legacy as guitar player and guitar musician is his religious and scientific dedication in exploring and fulfilling the potential of the instrument, changing the game yet respectfully never shifting the focus from the sacrality of song and music to himself. Striving for the most complete palette never forgetting the painting.
Among the contemporary shredders, he has the monk-like mindset of a XVIII century virtuoso.
For what is worth, he's up there in my pantheon with Jeff Beck, Rory Gallagher, John McLaughlin, Vernon Reid, Robert Fripp, Jan Akkerman, Mark Knopfler, Brian Setzer, Ritchie Blackmore, Steve Lukather and Gary Moore.