Driving drunk is particularly bad for how it can affect other people, but there are lots of dangerous things that people do while drunk that are also very concerning.
Who cares if some drunk guy kills himself behind the wheel because he's too selfish to make the right choice? It's when he kills a family with a couple kids in the backseat that we have a problem.
I think lots of people care. I didn't mean to make it a small point that drunk driving endangers other people, but I wanted to point out that there are lots of life-threatening behaviors between drunk driving and sleeping with someone you wouldn't have slept with sober. I also think you're being far too flippant about people killing themselves with their own poor decisions. It's not the same problem as killing others, but there are lots of people in the world who would still like to prevent deaths from drug overdoses, alcohol poisoning, single-party drunk driving accidents, and so on.