I agree it may be a bit more dangerous to wear headphones or earbuds in your ears and listen to music while riding. I do not agree however that it can be compared to a drunk driver. A drunk driver puts himself and whom ever he or she comes into contact with in danger.
If I listen to music while riding by myself on a lone rode, if there is danger, it is only for myself.
I live in the country and most of the rodes I ride have large shoulders on them. The traffice at the time I ride is minimal, and if someone is going to hit me while riding on that large shoulder they are going to hit me whether I hear them or not. I do however keep the earbud out of the side that is by traffic. I think there are exceptions in every situiation and everyone's is different.
The music motivates me and keeps me moving even when I am hot and tired. I am riding to lose weight and get healthy and set some goals for myself. I am not out there racing in competition, or riding the mountain trails with turns and bumps everywhere. In those cases, yes it would be a dangerous thing to be listening to music when you need all concentration on what you are doing.
Anyway, I guess I am just trying to make a point that situations are different and the rules aren't always set in stone.