Like @Tin_Wisdom I rarely reach this stage with games because I simply stop playing them once the appeal has gone, finished or not. If I’m really close to the end I might battle through it, but life’s too short. Any MMO or open-ended sandbox without a story will also eventually reach this stage, it’s usually pretty obvious to me when I should move on, so I just remember the good times I had with it.
The only exception really is when I’m really enjoying something and hit a difficulty spike so huge that I just can’t go on. It doesn’t make me hate the game, just disappointed in it. Thing is, I can’t think of that many examples because I just uninstalled them and did something else. Recently there was Cryptark, a game I really enjoy but which turns the difficulty up to 17 (that’s right, turning it up to 11 would be fair, this goes to 17) on the final level, and requires large amounts of pure luck to beat (so I’ve heard). I guess there’s also Ori and the Blind Forest.
Actually, there is a game that I really despise, but I can’t quite tell you why. Dungeons of Dredmore. I hate that game. I just… don’t like it. Weird. (one of the handful of games I’ve set to “hidden” in my Steam library)