Different people have different approaches to gaming. Not everybody will like the same things. For a game to work for those involved, there has to be certain kinds of positive chemistry.
Player/GM: GM's run campaigns according to their tastes. If a player doesn't work well with it, then that is not the GM for the player and that is not the player for the GM.
Group/GM: Same thing, only with a group focus.
Player/Group: Every player has to enjoy the group dynamic. If not, then that's not the group for the player.
Game System/Participants: If the content and system are not to one's liking, that's simply not the game for her or him.
I like the classify the experience on a three tier scale. At the highest, one is excited about the upcoming game. The event energizes before, during, and after play. This is the ideal experience.
At the mid level, the game is fun, but not energizing. When not in game, the general attitude toward is is neutral (one is neither excited nor bothered by it). If the game were to continue, that would be fine. If the game were to end, that would be fine, too.
At the lowest level, thoughts about the upcoming game leads to anxiety. It's just not fun. All it does is lead to frustration. Someone who is here emotionally is only going to bring the group down. Drama is inevitable. At this point, it is best to abandon the game, even if one is the DM.
Abandoning a game isn't easy. People usually play with their friends, and they don't want hard feelings. I recommend using lots of "I" messages and not laying blame. Something like...
"I recognize that not all gaming experiences are for everyone. Different people like different things. I've tried playing this game for a while now, and I'm sorry to say that the game really isn't doing anything for me. It's not anyone's 'fault'; It's just that I'm not connecting with what's going on. I think that, for me to have the fun I'm looking for, I'll need to play a different game. Sorry all, but I feel I need to bail."