What about cocaine? Heroin? Make their own Meth?
Where does it end? Legalize one drug, will not something new and exotic fill the gap?
I am really ignorant on illegal drugs, no personal experience and none wanted.
The issue is when you makes something that is in demand that makes people intoxicated, you drive the market underground and make gangsters rich.
I don't know how many times we have to go through this in the states before everyone gets it and ignorance is not displayed so widely on the internet and at the ballot box. Economics 101.
In answer to your 3rd question, so what?