There is some little
things a bit hard for me to understand sometimes.
it is true that in France we are contradictory on certain things, but
they're not better in the U.S. 
Like about alcohol
In the U.S you can't walk in the street drinking a bottle of beer, you can't also order alcohol if you're not 21.
I really agree with those rules. Ok, maybe if I was 20 I would say something else. But I can buy alcohol since a lot of years, so I don't care. :p
But, in U.S it is usual to go for a brunch on morning and drink Bloody Mary.
For me drinking alcohol on the morning mean that you're alcoholic or maybe that you're still finishing your last night party (ok, if that you'll look like an alcoholic too :p).
And also, we went on a water park with Richard and the kids during my last stay in Chicago. You know the kind of place with big play area, lot of kids, lot of noise. It's really a place for kids. Not a place where you go to have fun drinking a glass. You'll have fun, playing in the water with the kids for sure, but its not a lounge bar or a club. And there, i saw parents ordering cocktails like Margarita etc, etc...
For me if you go to spend time with your kids in a water park, you don't have to drink alcohol.
And I'm pretty sure, i was never looking about that so I'm not sure, but I'm pretty sure you can't order alcohol at water parks in France.
So, my guess is, if you don't allow kids under 21 to drink alcohol, maybe it will make more sense to don't drink alcohol in the morning, or at kids places.
But be sure that I don't agree with a lot of things we use to do in France.
Its a bit weird
as you're shared between different feelings.