In each case, prohibition creates more problems than it solves. I have to use two separate definitions, because the issues raised by drug prohibition and gun prohibition differ somewhat.
Medical benefits accrue only to small number of users.
Beneficial to public in hands of honest majority, discouraging home invasions, assaults on women, and massacres. Pleasurable to some hunters. One comment on the comments. The medical benefits of alcohol or pot certainly don't preclude them from being used irresponsibly. Not ragging, just poking.