I think I already spoke to your point, Snowguy...I have been that drunk person on the bus, and I got in no legal trouble for it. But I did my drinking in the bar, not on the street, or on the bus. I have no problem with anyone having a beer by the river, and in most cases, neither does the law. I think the restrictions that the law does place on where alcohol may be consumed, and how drunk a person may be in public, are reasonable. They are certainly not excessive.
The law as it stands leaves a massive gray area and puts the interpretation of the law into the hands of the cops and not into the hands of the citizens.
Despite the law being laxly enforced for people "enjoying a beer by the river", some angry cop with a chip on his shoulder could immediately start causing trouble.
I think the law should be made clear. And I think it should err on the side of giving people more personal freedom in this case.