Based on personal experiences this isn't surprising. When I was in college in a small town in the late 00's, many friends and acquaintances would drive across town after heavy drinking. 10-15 minutes, straight roads, little traffic. Other than not going out, or not getting home, you didn't have many options. It was a hour long walk or a $20-40 cab ride, if you could get one. I was recently back in town for a wedding…
Pretty irresponsible of someone to drive drunk to save $20-30. I could never imagine doing that over the options (riding a bike, ignore going to the bar in the first place etc).
Disclaimer: This isn't an excuse for drink-driving, you should think about this before you go out, but clearly there are a lot of people who either don't think about it or can't help themselves.