Given my experience with many solo RPGs and with a couple MMOs besides WoW, I'd say modern WoW is actually pretty gentle on the grinding curve than most games.  (Try playing Etrian Odyssey or FF XI, gads...)<p>I stopped playing after WoW after about a year not due to boredom, but frustration with end game content and game play emphasis during holiday events due to the new achievements system.  It really ruined what really was, for me, a laid back, semi-relaxing game turning it into a grunt fest.<p>For some, the "boring" content is more meditative instead.