Disconnecting:
>saps levels
>prevents you from getting any runes earned while you were disconnected
>leaves you far away from your group
>even removes all of your passive effects (e.g. "guard counters perform summoning attack")
So why the fuck would I ever reconnect to a game I dc from, even if it was an accident? The sheer fucking fact of being disconnected for a minute or two in this fast-paced game is enough of a punishment, why even bother when there's more of a debuff?