Drinking in public is OK.
Being drunk and a nuisance in public is not OK.
I wish we could adopt the same attitude back home - here in Norway you are likely to be fined for drinking in public (though the extent to which drinking is tolerated vary considerably from place to place), whereas you can be in a drunken stupor and mostly be left alone as long as you're not drawing a lot of attention to yourself.
Then again, our drinking habits are mostly a DDoS attack on law enforcement - everybody going out Friday and Saturday night at around midnight, bars close at 2:30-ish at which point thousands of drunk-as-can-be people crash onto the streets.
> Being drunk and a nuisance in public is not OK.
In my experience, this is basically the way it already is in many places in the US. As long as you put even a modicum of effort into complying with the letter of the law in front of cops (ie using a brown paper bag, putting alcohol into a non-obvious container, etc) and you're in compliance with the spirit of the law (ie not being a loud and disruptive drunk asshole in public), the cops will generally leave you alone and you can responsibly consume freely in public venues.
IME the result is the same. When we're young and stupid we drink in public because we have to and tend to over do it, then we learn that drinking in public is illegal and the lesson tends to stick even when we're older and not out to get blind drunk.