In a way I agree, there has to be a major deterrent for this level of negligence. That said, “ruin their life” isn’t IMHO the right way to go. I’d be happier if they kept living a productive life, but they’d better be supporting the people who depend on me.

You want them to learn their lesson but how do you do that without ruining lives? How do you do it before they kill two people? I think that level of change has to be governmental and even cultural. Reducing dependence on cars, increasing how seriously driving is taken, etc