WoW is a masterpiece. I have played on and off since launch, and have both raided and PvPd extensively in all expansions. Every time I come back, it's different. There is SO MUCH in that game, both in terms of explicit content (quests, raids etc) and nuances to gameplay (spec and gear variants).
I think the problem with WoW is, as Yahtzee says, 100 percenters. Whenever I was/am playing WoW, I say is this fun? If no, then I stop. I don't care about abandoning groups, missing content, whatever. I enjoy the learning curve of wiping, I don't enjoy carrying scrubs. I generally loath professions, and as such usually don't bother, or only do them while I'm doing something else. I have never, in 7(?) years, leveled fishing or cooking, and only once leveled alchemy because it was kind of fun for a while but got old.
Most people who have their lives ruined by WoW are people who play way beyond the point of fun. People who rage in BGs or rage at groups or troll general. People who lament the lack of balance. Most of these people are either children or adults who lead empty lives. So you would ask if WoW is causing the problem, or is it a symptom of a larger dissatisfaction.