We have a system whereby some drugs are legal for everyone, some are legal for adults only, some are legal only with a prescription, and some are illegal.
If a case can be made for moving a drug from one category to another, that can be done, and is done all the time. Drugs, for example, move from prescription status to over-the-counter quite frequently.
You do favor all drugs being legal, don't you? Including prescription drugs? Not just marijuana, correct? And to all ages, or would you arbitrarily pick a number and make that a minimum age? Could you then explain and defend your choice of that age?
I never made any since A then B arguement. I am arguing for consistancy, and if you can go back to the scheduling criteria and not see it being applied inconsistantly then I can reason with you no further.
All ages except minors. So yes, like all other things in society, people who are incompetent to make their own choices, good or bad, are restricted from that until they are competent. So, people pick arbitrary ages along with restricting the insane and retarded and senile.
In short, in a rational situation, someone as crazy as you would be restricted. :^}