I would. But not because I believe it is a good thing to use recreationally. In fact we know it is extremely bad for you. It's shown to permanently alter the human brain function in young people who use it even in a nominal amount in a recent Harvard study. However, that doesn't change the fact that people are going to do it any way. Tobacco is also bad for you, and so is alcohol when not used in proper moderation. Yet we haven't made it illegal for people who are dumb enough to poison themselves with cigarettes.
People make poor decisions. That's part of being free. If you drive under the influence and injure someone, there would still be consequences. If your employer finds that you came to work under the influence, they could also still hold you accountable. My issue is the large number of law enforcement resources we waste trying to chase after people who sell it. If there is demand for a product, someone will provide it no matter what. The best way to prevent people from using things that are harmful is by educating them...and some will always be foolish enough to still do it.
In fact I would legalize all drugs...on one condition. Don't ask the average John Doe citizen to pay for your rehabilitation via gov't funded programs or higher private insurance premiums for people who now claim they have a disease because they've burnt out their brain cells or become chemically addicted. If you're willing to poison yourself...don't make it my responsibility to pay for your stupidity. This cost of this type of treatment should not be shared by people with enough common sense not to poison themselves. There are enough kids in places like St. Judes hospital with real diseases that never had a choice. They need our help...not someone who chooses to voluntarily destroy themselves at a slower pace.