Zubon over at Kill Ten Rats has a post on giving games a second chance, it’s mostly about single player games but does mention MMORPGs at the end. The post asks if you give a game a second chance, and contemplates how much time investment is a factor.
For most of the MMO games that I have bothered to return to, I would say I’ve at least levelled half-way to the level cap (at that time). In fact for the games that successfully drag me back in with promises of the latest update or expansion, I normally have actually one capped character. That represents one measure of my commitment to the game, and my enjoyment of the games basic content and mechanics. I’ve made capping characters a bit of a focus in more recent years, indeed if I revisited this post now I’d score somewhat better (now 7 of 15, soon 8).
Games that I have never returned to would match well those that I didn’t progress deeply into: for example Aion, Blade & Soul, Diablo 3 to name some. This isn’t to say that not playing long enough first time around is the only reason I wouldn’t return to those games, I have differing reasons for each, but it does show I didn’t take that long to either decide against playing further or to grow tired of the gameplay.