The way I look at it, I've spent whatever on the game. $60-70 new, I usually buy used games as insurance against this so I can get 2-3 at the same price and have less chance of disappointment while trying out more different games. That's not coming back. I don't know of a place anywhere around here that will refund, as opposed to exchange for the same thing.
So that sucks. But then I have a choice: Do I also blow 8-40 hours finishing the game? Working time, that amounts to $80-400, but screw working; it amounts to 8-40 hours I could be spending drawing, reading, playing a better game. And once I finish, then what? Do I buy the next in the series even though I hated this one? If I don't plan to buy the next game, why would I finish this one?
This is an aspect I dislike about achievements and gamerscore. For a *while*, note not anymore, I actually did keep playing games I didn't like, grinding through them to get the extra points. Notably, the games I didn't like had re-e-eally easy achievements to get. Like "Beat story mode - 100G" and "Complete tutorial - 5, 10, and 15G". But that's my own fault.
So no. Right now and for the foreseeable future, I don't blow any more time on games that disappoint severely. Especially when the problem often comes down to clunkyass controls.