Should employers discriminate against World of Warcraft players?

On a gamer forum, a vigorous discussion about whether it's fair for employers to discriminate against World of Warcraft players when hiring, on the grounds that WoW players are never fully out of the game. A surprising number of players agree with this proposition.
I met with a recruiter recently (online media industry) and in conversation I happened to mention I'd spent way too much time in the early 2000s playing online games, which I described as "the ones before World of Warcraft" (I went nuts for EQ1, SWG and the start of WoW, but since 2006 I have only put a handful of days into MMOG playing - as opposed to discussing them - I've obsessed over bicycles and cycling instead).

He replied that employers specifically instruct him not to send them World of Warcraft players. He said there is a belief that WoW players cannot give 100% because their focus is elsewhere, their sleeping patterns are often not great, etc. I mentioned that some people have written about MMOG leadership experience as a career positive or a way to learn project management skills, and he shook his head. He has been specifically asked to avoid WoW players.

Topic: Recruiter told not to hire WoW players (via Raph Koster)