I have to say, I agree with Stylewalker here... although for different reasons.

One of the reasons that WOW is successful is that it is constantly reinforcing a persons ego by having them reach milestones every time they turn around. You may not like training that weapon up, but you feel a sense of accomplishment when you do. You might not like attunements, but you felt like you accomplished something when you got it. WOW is successful, because like in life, there are a vast number of opportunities to feel as if you overcame a difficult challenge. Many of them are big and easily recognizable, but a large number of them are small, hardly noticable by themselves, but the little ego boosts add up.

Agent Smith in the Matrix had one thing right. We define ourselves by the obstacles that we overcome... the challenges that we struggle though. Opposition in all things, right? You can't know joy unless you know sadness, etc. People that play video games in GOD mode will bore quickly. It might be fun to be unstoppable for a little while, but soon it is mundane because there is no challenge, no struggle, no work, and no appreciation. Isn't that the whole point of them putting in accomplishments? A large number of lists of things for you to grind through? People talk about how fun or cool that will be. Why? How is grinding up a weapon skill any different. They are both time sinks, and can become mundane. I just know that I feel good about myself when I finally max out a skill or trade. Even if the grind pissed me off... and sometimes especially if it pissed me off. And this translates into real life activities too.

WOW is successful, not in spite of the annoying little things we have to work through, but because of them.