That's an interesting point of view... Here's my ramble:
I agree that the term itself - 'virtuoso' - is thrown around here a lot, attached to players like Satch, Vai, Gilbert, etc. From context it looks like a lot of people (or at least a fair amount) base virtuosity on how fast someone can play. Musicianship and taste get thrown out the window; at this rate the next virtuoso could very well be that Japanese dentist in Kevan's/Ross's thread. :sarcasm:
IMO the value of the term is being degraded by every new person it's attached to. If it continues like this then what is the value, the point, of being a virtuoso, if a six-year-old can be one? I think "virtuoso" was meant to be really honorable title, but it doesn't seem like it anymore. I agree somewhat with Jay's point about how practicing to be a virtuoso is a little self-defeating.
I value virtuosity mostly on innovation, personal style, influentiality, and technique (but technique is not
the most important aspect). For example, Bach was among the first (if not the first, ... but I'm not exactly sure) classical composers to base his music around modern music theory. The music wasn't extremely technical per se, but it was innovative, springing forth "clones" like Haydn and Vivaldi. Sure they had their own personal style but their music was in the same vein as Bach's (as if they were influenced by him); therefore they were not as innovative and not as virtuosic (still good though!
Fast-forward a couple centuries. Early 1900's - Robert Johnson. Personally I can't stand the blues but it's pretty safe to say RJ was among the first to establish that kind of musical style, and he was very influential, from what I have read. Plus if you base your definition around 'natural talent' (like Jay said), Johnson meets that criteria too - he was born with unusually long fingers, plus it's rooted in legend that he sold his soul to the devil for his 'overnight technique.' Now the story is probably a farce but the overnight technique has to be a natrual gift of some sort.
Moving on... Jimi Hendrix. I don't like his music, and he certainly wasn't a very technical/theoretical musician, but his music was pretty innovative at the time, for the most part. Also, he is probably one of the single most influential guitar players ever (Satch and Vai along with many others cite him as their biggest influence). In addition to that, his name is extremely well-known. You'd have to be living under a rock not to have heard of Jimi Hendrix.
Please note these examples were the best ones that I thought of on the spur of the moment; IMO there are quite a few more.