I think you primarily run into two issues with this. The first is somebody getting killed is a little late to start giving somebody a hard time about drunk driving. I think the argument here is that prevention is much, much preferable to punishment.
For best results this should be tied to the observation that, assuming one is on a public road, you actually don't have a personal "right of way" for any action deemed hazardous to others. One could argue driving impaired isn't that far removed from, say, deciding you don't feel like acknowledging Stop signs tonight. Get plastered, run lights, throw the comical idea of "yielding" out the window, what's the difference? As long as it's a public domain it can at least be argued that it's entirely fair (correct even) to take steps (enforce certain rules) to protect the public at large against those who might jeapardize others through unsafe action.
I'm not a fan of infringing on any freedom but when I get in a vehicle and go drive it's not MY road any more than anyone else's.
Anyway, that's just what I think the other side of your observation might be.