I support the Portuguese model of decriminalising small amounts in possession and criminalising the big dealers with harsher sentencing.
Which makes no sense, logically.
If the stuff is legal to possess, where are people supposed to buy the stuff that is legal to possess from, if not from dealers? If that dealing is illegal, where does the money that the legal possessors spend end up? If that dealing is illegal, what reason is there to believe that the products being sold illegal are what they say they are, free from impurities and correctly dosed?
Legal possession, illegal sale forces a link between the legal overground users and the illegal underground suppliers. It's that linkage, with the flow of money from purchasers who see themselves as upstanding citizens doing nothing wrong, to gangland criminals, which makes the whole thing so toxic.
If you legalise possession but make the sales themselves illegal, you are simply making it easier to make a living as a drug dealer because your clients have less reason to be furtive and no reason at all to turn you in. When possession is illegal a dealer runs the risk of being given up by a user looking to avoid a prosecution. When possession is legal, your clients aren't getting arrested so (a) can't turn you in and (b) can continue to buy your product.
Yes, it avoids cluttering up the legal system. Yes, it arguably reduces some harm to users, although they are still at risk from contaminated, adulterated and, paradoxically, the occasional pure dose. But if your intent is to put drug dealers, and their associated violence, out of business, legalising possession while leaving dealing illegal seems to combine all the worst facets of prohibition with all the worst facets of legalisation.