"Life, Liberty and the pursuit of Happiness." is such a wooly useless statement though.

You could argue that based on the above, the US shouldn't have a minimum age limit for alcohol since it clearly infringes on teenagers (heck even college kids) pursuit of happiness.

I'm not arguing that it's correct that they have strict laws about pornography, nor would I argue that it's incorrect that the US has strict laws on alcohol. It's up to each country where to set its own laws.