This totally makes sense. See unexploited market, then focus on exploiting it.... I don't thinks so....
Ten years ago only "geeks" like myself used to have a PC and know how to use it and play MUDs online. Since then the market has changed - more and more people have at least one computer in their house and Internet. Where games used to be for a few dedicated hardcore games before, they have since changed to cater to all (or at least try to cater to all).
I've also been a huge WoW fan in the past and seen it grow from game catering to hardcore gamers to catering 13 year olds. Don't get me wrong, there is still content to hold a hook in for some of the hard core gamers, but with every patch and expansion pack it's less and less. As more and more games become so generic to try and hook larger demographic, new games will start to come out that will focus and specialize on hardcore gamers, casual gamers, kids... etc. Games with broad appeal will die, as a game that does not cater to and individual audience will not hold anyone's interest. Sometimes by trying to satisfy everyone, you don't satisfy anyone... MMOs market is still in it's infant stage...
Games, like movies are made for niche market - specific audience, and Blizzard is just greedy. How many people would watch a movie that contains all of following: porn, sci-fi, fantasy, comedy, drama, thriller, action, gore.... I'd rather watch one good comedy, or one good action movie than any movie containing all aspects of the genres.
Blizzard will fail if they don't start making individual audiences happy with their games. In ten years or less WoW will turn into a MMO Whack o Weasel.