It's popular all over the world. As far as video games go, it's pretty cheap; just as soccer is a very cheap sport to play. It's popular with all types of people for all sorts of reasons.
Some play it to hang out with friends. Some play it professionally and will play with only the best. Some play it purely out of love of the game. Some play it for exercise or to pass the time. Some play it to be better than others. Some play it to be better than they were.
Sounds great, right? Well sure, if it's soccer. Soccer has leagues and teams and all sorts of segmentation. We don't have the World Cup played in an alley in Brazil.
WoW doesn't have that. We're all in the same world. We're not all sure who we are, how good we are, why we play. This creates two problems.
First, we're in the same place. We've not put the professionals here and the kids there and the social players somewhere else. We're all thrown in together. There are plenty of courts, but with no rules for them, we fight. The kids play here but the professionals think it looks nicer so they try to take it and then there's conflict. The social players have been sitting around chatting for the last ten minutes, and sometimes they use their hands, so the guys who are trying to practice get pissed at them for wasting the field.
Second, we learn behaviors from each other. So kids who want to play with friends are next to professionals and they keep getting made fun of. After all, the kids aren't especially good (though as an American, they'd run circles around any team I was ever on) and look dumb compared to the professionals. It hurts to be constantly called a little kid and told to play somewhere else. So they try to fight back the only way they can: they try to become like the professionals. They want to play as well as them so they can keep their field. But not all the kids want to do that, so they don't play for so long and aren't as good and then they are pushed out of the team. No one ends up very happy.
The professional players lose a game and scream at the kid who ran onto their field. But the kid was just trying to get his ball, it went loose. And besides, he was just trying to practice that curve ball that the professional used for that one goal.
We'd all be much better off if we drew up some lines. You play here and we play here and they play there. WoW has plenty of fields. It has plenty of balls. If you want shin-guards and special shoes and those things so you don't break your teeth, that have those. There's enough for everyone. But we don't see that well enough, so we fight over the rules and space and all get very angry and unhappy.