WoW was a new type of game for most people who had never played EQ, or MuDs, etc. But WoW is way old now and the vast majority of players don't care about the old stuff. Even most of WoW's playerbase moved on to newer games and game types a long time ago. If they wanted more of the same then Wildstar would have been successful.
Repeating what was done before only works for small niche audiences. Imo the next huge MMORPG will be a totally new experience that has very little resemblance to EQ, WoW or any of their endless clones.