Because on planet earth it's called the "presenter" for a reason. You wouldn't watch it if it was some hairy pitted fat chick with moles on here face, would you? Usually a "presenter" of a show, especially a topic-specific show, should be a sort of representation (see the word presenter in there?) of the demographic related to the show.
Not all gamers have tattoos and piercings covering every square cm of our skin. It's giving the wrong impression of what gamers look like and what we're into. We're not all geeks with pocket protectors anymore, but we're also not a bunch of heavy metal painted and pierced goth-like people either. YES, I know you might be, but a presenter needs to represent the demographic as whole.
My reasoning is pretty sold