Laws and Taboos

I've always looked at laws as being in two categories. Laws are either in the "yeah of course obviously" category (like murder, stealing, etc) or they are in the "well I guess" category "J-walking etc." A lot of the time, these "well I guess" laws aren't heavily enforced but are rather there to deter most people. In the U.S. people can drive before they can drink. In many European nations, drinking is allowed earlier than driving. With this in mind, it seems that to the U.S. drinking is more taboo and so it is pushed farther away from teens/youth. In some European nations, it seems as though alcohol consumption is more accepted and because of this, it is allowed at a younger age. This idea of laws ,that should affect individuals equally, being altered based on where the law is implicated seems kind of inadequate. I understand that laws such as J-walking can';t be equal everywhere because of things like automobile distribution and how rods are in certain places. It seems odd that laws for human health are different and not standardized for all people everywhere.