You clearly haven't taken the time to be informed on this topic. I'd suggest you start by reading a few of the downright comical assertions about marijuana that were used by Congress as the basis for passage of the Marihuana Tax Act of 1937. They didn't go quite so far as to say it will turn you into a bat, but close.
The only reason it was legal was because it was only used by a very small percantage of society. Several other mind altering drugs including cocaine and heroine once enjoyed that status. Do not irrelevance for acceptance.