I believe it has to do with the weights of the punishments.
Although, I will remain neutral in the argument. Drunk driving has the high chance for manslaughter, so could be considered equivalent to attempting murder. However, murder is murder, and should have a larger punishment than chance of murder.
Of course, in the grand scheme of things, we have no way of preventing the drunk driver’s death because it was “more of a punishment”, for the obvious reason that it already happened.
In other words, a dickhead is dead and there’s no changing it, so no need to argue about “it not being equal”
You know, you’re a real piece of work.