Is it that the illegal marijuana is safer than the legal alcohol? And the only thing keeping Alcohol in this framework is tradition?
Personally I am all for full legalization of recreational and medical marijuana. It's always been a way to give power to policing and circumvent the constitution by providing reasonable suspicion and the ability to seize possessions without due process.
But, I have seen some drastic personality changes in friends who start using it habitually. Without the decades of research we have for things like cigarettes and alcohol it's hard to know that it is really safer. Although it is a pretty low bar to clear considering how many people are killed or ruined by them every year.