As a gamer, I'm a victim of my own perfectionist mentality. I firmly believe that if you're going to do something, then do it right. After years of playing thousands of different games in dozens of different genres I've pretty much got this down to mixture of somewhere between a science and an artform, although sometimes I find myself limited by by own demands on myself. I'll find myself making a conscious choice not to play a particular game, even though I enjoy and admire it, simply because I know through previous experience the magnitude of demands it will place upon me to do it right.
Much of this depends on what my personal goals are in a particular game, and this is where I can somewhat get around my own self-imposed perfectionist demands. This especially comes into play when trying out new titles as my goal is simply to learn about and experience firsthand what the game has to offer, and to have fun doing so - hopefully! Nothing more than that, just explore the game's world and features and how it handles the new player experiences. Once this grace period has ended, the time of which will widely vary depending on the game, I'm faced with a decision based on what I've learned so far - the decision whether to continue onwards into forward progression into mid-game and then ultimately end-game or to move on to something else. This threshold tends to move a bit depending on the number of current game offerings. During slow times in the year when new releases are few and far between I'll be much more inclined to stay with a game, since there's not much else of interest to get involved with, and alternatively during those times when it seems like there are 3 or 4 simultaneous releases of major games it's much easier to jump ship to try a new offering.
When I do decide to stay with and further progress into the game, well that's when it starts getting real. I'm not going to settle for doing something half-assed or flat-out wrong, that's just a huge waste of time and effort that could be better put to use on something truly worthy of the cost. Usually at this point right after decided to continue onwards, a goal I will have is to progress forwards entirely through my own personal solo effort, without entirely ruling out non-solo group efforts. Mainly though I personally dislike having to rely on someone other than myself, and attitude I've gained throughout life in general and gaming in particular. If I can see a path forwards through mainly solo content, with perhaps a small smattering of co-op then I'll likely stay around for a while as long as all my other requirements (engaging gameplay, decent depth and customization, good performance, reasonably sized playerbase, art design, etc) have been met. Even with these requirements there are still a good number of games that meet them all, which means some games that I want to play simply get left behind because of time constraints.
The games I intentionally stop playing or uninstall usually have a chosen to take a certain path which I can see ahead of time will only lead to a dead end. A dead end game. Sometimes, but rarely, a game which otherwise fully passes all my other personal requirements for being a great game and worthy of my time and effort is actually a dead end game. In other words a game where I can see far in advance that there is going to be a huge wall that the player will hit. More often than not that game's wall will be a requirement to pay (often huge sums of money) to truly progress forward. Oh, you'll still be able to putz around with some crafting or daily quests, but actually moving forward will be next to impossible even if you throw huge amounts of time at the wall, the wall won't budge. After spending literally thousands of dollars into game after game (sometimes even into a single game) it's a road I simply will not go down anymore whether I like the game or not. I might love the game but if there is a wall somewhere down the road then forget it. And I'm an expert at seeing these walls even if they are invisible to most other players until such time as they actually hit them. I can see them well in advance through a combination of wisdom gained through personal experience, and research.
Research plays a huge role, and usually it's not even that difficult. With forums, YouTube, and guides put together by more advanced players from overseas which have played the game in advance of a stateside release, you can really put together an accurate picture of what getting to late-game progression with entail. And sometimes it's just not pretty. Doing it right means crashing up against and then through a wall that is just too thick by design - the developers have created it that way on purpose and you either go through it or crash to a halt. The decision at that point is whether all the other game elements that are so awesome actually warrant the time, effort and currency to proceed. There are very very few cases where the answer is yes, almost next to none.
Thankfully there are tons of good games just waiting to be tried out, all vying for our attention at the same time. There is even a growing resurgence of sorts to older ways, surely a backlash against the current over-homogenization "no effort required" money-grab style games that are so popular with the casual mainstream audience. These new "old-school" games often prove to be well worth the time and effort, with the added benefit of making it much easier to be a perfectionist gamer and to actually do it right.