"Gaming" is not the thing that ruins your life. Your choices are. Heroin itself doesn't ruin peoples lives, it's a person's choice to use it. Obviously some things can "hook" you harder than others, but it all boils down to self control.
It's my belief that if you're the kind of person that gets completely hooked on WoW (to the extent that you neglect your schoolwork/family/girlfriend/whatever and it's having a negative impact on your life) then you're the kind of person that would get hooked on plenty of other things if WoW weren't around (other games, drugs, collectible card games, etc.). People that are like that want something to obsess over... for who knows what reasons. Obviously there's some other issues playing in the background.
If it were all cocaine's fault that people got addicted to it, then everybody (or almost everybody) who ever used it would be coke-heads. Obviously that's not the case, and everybody who's careful should be able to muster up some self-control.
On a sidenote... if you're playing games so much that it's having a negative impact on other things, you need to take a look at what exactly you're trying to escape from, and maybe see a counselor.