[shopkins]

I only have anecdotal evidence, but offer the heuristic that most "drunk enough to be dangerous" bicyclists can't ride fast enough to maim anyone -- and if they're riding down a hill, they're much more likely to be maimed.

There's an inherent barrier to entry that makes drunk biking difficult enough to limit those who can actually do it. Like how often do you see someone drunk on a road bike with clips? How many drunk people bike on busy roads where they're more likely to get killed than the guy in an air conditioned hunk of metal on wheels?

A reasonable person's analysis might conclude that it's better to say, "hey, let's bike to the bar" that's 4 miles away rather than "let's drive," because statistically you're as/more likely to fall down and injure yourself as if you'd walked, and will harm society much less than if you'd decided to pilot a machine that requires a fraction of the bodily coordination to get from A to B.