The legal limit in most of the US (0.08 BAC) is actually pretty high, so you can legally drink and drive. For example at that level a 220lb man can have four (American 1.5oz) shots and hit the road immediately at ~0.7. So most drinking and driving you might have seen probably isn't (at least legally).
The second main reason is probably because there is no good mass transit. Most other countries either have the local pub you can walk to or some subway you can take - there's no 20min drive to meet somewhere.
The legal limit in most of the US (0.08 BAC) is actually pretty high, so you can legally drink and drive. For example at that level a 220lb man can have four (American 1.5oz) shots and hit the road immediately at ~0.7. So most drinking and driving you might have seen probably isn't (at least legally).
The second main reason is probably because there is no good mass transit. Most other countries either have the local pub you can walk to or some subway you can take - there's no 20min drive to meet somewhere.