We would all love that to happen but unfortunately , it is not viable at all. You have to have some sort of regulation if you want society to accept drugs, without regulation , you would end up with all those fears that the anti drug mongers fervently sell coming true and beating the whole purpose of legalisation. Criminals , people who do not have the means to suppirt their habit financially , Seriously mentally ill, people with history of addiction and serious abuse, these are the kind of people that need to be regulated for NORMAL people to enjoy their snort of coke or a pill of scstacy or whatever without being stigmatized by the society.
There is regulation everywhere , you need to be a certain age and clear a driving test to be eligible for a drivers license, you need to undergo a background crime check if you want a passport/Visa , you need to be 18/16 to buy liquor , 18 to smoke , you get my point.
Don't you think it is highly irresponsible to to allow the free sale of drugs without ascertaining what kind of people are having access to it?