Yeah, in general I don't overly object to players throwing, or partially throwing, the game as an act of revenge. This puts weight behind threats of vengeance, which if they were never followed through upon would be of negligible use as a diplomatic tactic.
If I end up with a Survive because a rival player threw the game, that tells me that I either needed to have stabbed them more thoroughly in the first place, or that I needed to step up my diplomacy.
And, on the other end, it can rather satisfying to see those that screwed you over go down in flames. Next time, maybe they'll think twice before messing with you!
Finally, bitter feuds make solo attempts far more interesting! There is nothing quite like, as the leading player, welcoming with open arms the player that the others have outcast. Similarly, as the head of an anti-leader-alliance, it is an interesting challenge trying to get your unlikely allies to work together.