Question for you..
If you're a dragoon, you grab a duty finder Titan, and you die at 10% but the group clears, did you deserve the win?
Now, if you're a dragoon, you grab a duty finder, but one of the healers always dies at 10% and that domino's into a wipe, you don't deserve the win?
Job doesn't really matter in the scenario, just picked a job for easy example that isn't as vital to brute-forcing through a win as say the tank or a healer.