I'm not trying to push the envelope here, but this falls under the "I've done it, so it isn't that bad category." There is a part of me that understands this.
The bottom line is and always will be, if you're going to drink or have had something to drink, don't drive.
The person who does what you describe above isn't a lowlife simply because nothing happened. All of that changes when something does happen. Tell me truthfully, if someone killed your child and the BAC registered .068 (pretty well below the limit) aren't you still going to wonder what that person was doing behind the wheel?
Not driving after you've had drinks is the only moral and ethical answer. Nothing from the store is worth the risk. I wish people did not go to bars to drink. I really do. I prefer they go home FOR THE NIGHT and have their drinks where they can't possibly hurt someone. I have yet to figure out how to stop someone from leaving someone's house after drinking other than the taxi rule. I wish people would abide by this.
It simply isn't worth the risk. Now, have people driven and not hurt someone? Sure. It happens constantly and I'm not naive. I understand what Adam is saying though. At that moment...you have to wonder. You can object to the word low life, choose another word, or simply choose to be offended by it. I don't think any of that changes the fact that if someone has been drinking they should not get behind the wheel.