Well what about the violin? You can do a variety of things on it with different techniques. In fact, one of Paginini's 24 caprices has the violin player (I have a recording of Isaac Perlman playing it) plucking the violin like a banjo or guitar.

I think that a lot of people don't like classical because they haven't really heard that much of the good stuff, only cheap condensed versions of Beethoven's 9th symphony on commercials and Beethovens Fur elise, or 2 seconds of Vivaldis four seasons (spring) on ads for country clubs. A lot of it is image to. Most kids today live in a society where "classical is not cool..."

And if you look closely at it, shredding on guitar has a lot of parallels to the whole orchestra, "play this way not that way" thing. There is a proper technique for everything, which I have heard a lot of the shredders on this forum talk about (IE alternate picking, hand position...)

If you want to hear how musicians really push the limit on their instruments and how they should be played, check out jazz. A kid that I knew who played the tenor sax, who is incredible and now off at college, really showed me this. For those of you that don't know anything about the saxaphone, the highest note, generally, that they can hit is an F or F#, depending on the model. In one of his solos, this kid hit an A above that F#, just by producing a squeak just right, he meant to do it! Talk about being free with your instrument...