Good question with an easy answer: yes.
1) It's safer than both alcohol and tobacco, and impossible to overdose on.
2) It's not physically addictive, making it as "addictive" as chocolate or sex.
3) It has dozens of accepted medicinal uses.
4) Throwing people in prison for using a recreational drug that is leagues safer and less addictive than alcohol and tobacco is silly and hypocritical.
Those are the best four reasons I can think of right now, but there are many more.