It is much more popular in other games, but the rage DCs usually happen when the person is so fed up that they aren't planning on playing that game for a while. There is a problem with a lot of Fighting Games that if you DC right before the match ends properly(losing, watching the losing animation etc..., takes about 15 secs or so) then it doesn't count as a loss on your personal records. You would play against the biggest scrubs who were sooo bad and they would have a 100% win ratio... Its just like come one man, even like the top 3 players in the world wouldn't even have higher than like 80% for online play something.
Most games have systems that automaticaly make it a loss with a DC, and luckily Duelyst is one of them.
I have only seen what I think are a few "Rage DC's." if you get salty you usually just concede and play a new opponent, but if you are super salty then you just alt f4 and go cry in the corner.