> If I had a dollar for every DUI story I've heard that involved getting pulled over "a block from home" after rolling through a stop sign..

If a cop suspects DUI, I want that driver pulled over even if they're entering their own driveway. "But I wasn't going to put any more people's lives in mortal danger by my recklessness tonight" is not a good argument. And keeping people from recklessly endangering others, whether by penalties that make them think twice or by taking their license, is one of the most basic reasons we have police at all.