Probably because the purpose of FreeRepublic is not for the advocacy of drug legalization for the spoiled and jaded.
--- Wrong again, cultist. FR is dedicated, in part, to exposing how our government is abusing our constitution. The 'drug war' is a massive part of that unconstitutional activity, and is thus a legitimate topic.
While that is not in contention, the fact is all we see from the libertarian ideologues here are moral-liberal arguments for allowing people to destroy themselves. That is a far, far cry from what, say, the Constitution Party advocates, since they are not moral-liberal ideologues as the LP members are.