The ESP Guitar Company

I recently got into a disagreement with some YouTube users on an Yvette Young song she created as most of her songs deal with a "tapping and sliding" technique to create her music (here's an example). I think she's incredibly talented, and that's coming from a metal head and punk aficionado, but some feel that style is "all over the place," and not really a great technique. Then I saw this guy John Gomm, and he's on another level I never saw before (here's another incredible example)! So my question is, why put someone down by the way they play music? Is it genre biased, or simply people don't like unconventional patterns in their styles?