Your statement seems pretty judgmental.
But yes, we agree don't drink and drive.
The police are almost never going to police restaurants, bars, wineries, and other such places even though there will obviously be plenty of potential drunk drivers to arrest. Meanwhile, a friend who parted ways with me after a night out stopped by a liquor store on the way home and was questioned and subsequently arrested (he was legally drunk) as he came out.
The point of this story is that the law states absolutely clearly that noone is allowed to drink and drive. On the other hand, practicality and reality means police will turn a blind eye to certain areas while enforcing the law elsewhere; knowing this is how the real world works is handy and important for what I hope are obvious reasons.
What I mean by this is that when people go out to eat lunch or dinner, they drive to the restaurant. They obviously need to drive back when they're done. They obviously also had some good drinks while they were there; beer, wine, the works. Even just a sip of alcohol will count as drunk driving, legally speaking.
The police largely turn a blind eye to this, because it's so utterly commonplace and a fact and part of life that policing this would quickly lead to a community and public revolt. Restaurants also happily serve alcohol because drunk driving is not their problem, and restaurants that don't will quickly go out of business anyway.
On the other side of the coin however, if you drive to a liquor store at an ungodly hour the police will be on you in an instant to check if you're driving drunk and arrest you if you are. Why? Because everyone wants or needs to eat and drink, but nobody needs to drop by a liquor store at 10pm.
The police will also check if you're driving drunk if they see you on the road and it's blatantly obvious you can't drive straight. This should go without saying, though; and it means most people who drink at restaurants can drive safe (FSVO safe).
Obligatory IANAL, obligatory don't drink and drive disclaimer.