America has a very long history of alcohol consumption. Thats why a blind eye is often turned towards drinking in a public park...as long as it doesnt become a nuisance. And I believe that was what the OP was saying...there are people just filling up trash cans with bottles and cans, and sometimes fragrantly littering. That's wrong.
There's a huge difference between having a few beers during a round and a group of 10 guys each pounding down a sixer, then maybe a few more. My main concern isn't even them being loud or obnoxious...its them DRIVING HOME after the round. Unless they walked to the course, that means they are getting behind the wheel of a motorized vehicle after consuming large quantities of booze. I'm rather certain that is why public consumption laws exist in the first place. Unlike Europe or Asia, America and Canada do not have outstanding, cheap, convenient public transportation options. That should be the real concern, in my eyes anyway.