Lets face it, one can more easily drive when they are totally snookered than bicycle. All the agility needed to plow a thousand pound car through the streets, is the tilting of the big toe towards the gas pedal. This creates a very deadly weapon( generally with no intention to maim or kill, but quite likely to do so). Get drunk enough, you can't even sit on a bike. You might kill someone that is trying to avoid hitting you, but you are far more likely to harm yourself first.
I'm not sugesting that I want a bunch of drunken cyclists out there, but I'd much rather face streets full of them, than car drivers who are bombed out of their brains. Unfortunately it's the latter that I see gunning down the sidestreets in vast numbers every weekend night, when I ride home from work after midnight.