Do you come with an interpreter?
Children enjoy special legal status in this country. It's the way it works. By your standars, statutory rape laws 'promote' sex amongst adults.
When drugs were legal, no distinction was made as to age. Up until 1924, for example, heroin was legal (and AMA approved). Just plain old legal -- not "legal for adults only" or "you must be 21" or even "prescription only".
MrLeRoy has called for drugs to be "re-legalized" (I believe that's his term), but for adults only. Here's the question to you: Why "adults only"? Seriously.