What is "acting funny"? Speeding? Changing lanes without a signal? Fact is, cops pull people over all the time for all sorts of things, whether they're driving "erratically" or not. Thing is, a guy driving 30 miles over the speed limit, changing lanes without a signal, cutting off drivers and breaking suddenly for miles gets nothing but a ticket as long as he blows under the legal limit. But the guy going 10 miles over, driving otherwise normally, gets his ass hauled into jail simply because he blows a .08. *That* makes sense to you? Why isn't the other guy--the one who was actually driving erratically--going to jail? Because the law is assinine.
You're wrong. A guy driving 30 miles an hour over the speed limit who is also cutting off drivers is going to spend the night in the drunk tank whether he blows a .07 or a .00. The police would ticket that guy for "reckless driving." His punishment is likely to be the same as the guy who blows a .08.
BTW if you knew everyone on the road had a .08 BAC, would you let your teenage children drive on the road with them?