Yeah bud, it's all just tools anyone can learn - if that were the case everyone would play like MJR, but the truth is there are only a handful of people who can actually technically pull it off. I mean how often do you see a you tube video of someone playing Symphony X and its technically perfect? Almost never! I never saw anyone making a huge deal about the kid, but it's still cool for a kid that young to be ripping Symphony X on the guitar.
Oh, and screw that whole fucking 'he needs to stop and play with a metronome'. It's important to work with a metronome and get your timing to be accurate - BUT you don't have to do that 100% of the time. It's not the end of the world to screw off and play something silly and fast and sloppy every NOW AND THEN. In Petrucci's video he even talks about playing faster than you can and fucking up just so you can get your brain up to speed and then slowing down feels far more attainable.
Also, anyone who isn't just being cliche about classical music and actually knows a thing or two about theory and composition knows that Mozart is so unbelievably mathematical and obvious its not even funny. You can say his stuff is beautiful and brilliant, but learning to write and arrange like that is almost as 'technical' as physical play on an instrument. Theme 1 antecedant, theme 1 consequence, theme 2 (this time minor) antecedant, theme 2 consequence, minuet and trio, recapitulation, modulate to the dominant, conclude back in the original key of the piece.
People spend so much time swooning over emotion in their playing and usually you hear those people and they sound stiff and awful and their definition of 'emotiona' pretty much equates to 'melodically slow'. People who listen to this genre need to stop having such a big bug up their ass about other people's play when all they are presenting is some little clip of themselves playing a lick or two, and not their magnum opus.