I agree that smoking mj could be a health issue for those who don't balance out that action nutritionally, but those who don't smoke it can always eat it like a vegetable, or make tea, etc.
It's not addictive, but people can get habituated to it, just like they get habituated to eating meat, or chocolate, or other things that are far worse for them.
I think we should all be able to grow our own and screw the cartels.