The issue with allowing people to do...well whatever the choose with themselves is that most people don' have the knowledge(Well all people), to make the right decisions most of the time.
What is the right decision? Is there such a thing? Is it not simply a matter of getting high or not getting high and that neither are a right or wrong decision?
We are bound by our own biology, so we cannot have 100% freewill, knowledge, freedom etc(If we did, then you extremist Libertarians would be right, but since we don't the vast majority of you are wrong).
I don't understand what you are trying to say, but you're of course welcome to explain. But I certainly don't think the idea of legal drugs is extremist. I think it was extremist to ban those drugs and brainwash society toward being against them, even to the point where now it's considered extremist simply to think that all drugs should be legal.
An example is this: A uneducated person is persuaded by a peer to use Opium because in the short term it gives "benefits" such as relaxation, pain relief, reduced anxiety and impaired alertness and coordination. The person doesn't know any better because of his ignorance, so he goes ahead and takes the drug. Several years past and his body becomes more and more tolerant to the # of doses he has been taking, so he ups it continually, all the while his body becomes more tolerant and he is severely addicted(A wide variety of "hardcore" drugs are extremely addicting, to the point that after a certain period of time using them, your body physically depends on the drug or you will go into withdrawal and possibly die). The person gets to the point that he gets cancer, heart attack, has an overdose, and dozens more(A lot of which are fatal).
It's life; whatever happens happens. A lot of people live into old age with opiate addictions, by the way. The problems arise from lack of availability. Hence, why some governments supply heroin to addicts and help them find addict-friendly jobs.
Overall, my point is that people are not limitless creatures that know all there is(such as the effects or outcomes of doing this and that, etc), so, there has to be certain rules that people must generally abide by, or risk destruction of themselves and communities, so no, drugs should not be legal(mostly because of the dependency/highly addictive part, where after certain longterm use your body physically depends on the drug).
The people who set the rules are people too. And generally, the highest IQ people don't have much to do with making those rules, since they gravitate toward professions other than politics. Do you have so little trust in your own mind as to rely on rules created by people who don't even know you and probably don't even care about you?