Do you really think that? Do you really think people should enforce their own penalties on other people? This is what you actually believe? Or is this just vapid bravado "he got what he deserved mmhmm"?
In this particular case, yes, I agree. (assuming all statements are correct) I feel like the drunk driver got what he deserved. It's not like the drinking age is new or "don't drink and drive" is new. He knew what he was doing and in doing so, killed 2 kids who didn't have a chance. Screw him.
In general, no. People can't be left with no laws. Anarchy is impossible to live with, but I do not like people who thumb their nose at the law, as if they are above it.