It's a little different because what "did in" tobacco - got them sued - was lots of tobacco companies making false claims, and claims they knew to be false, to cigarette users and the public in general, along with burying and denying health risks, targeting minors, etc.
I don't see the MJ sellers making the same kind of claims, and there is lots of attention being paid in the public to the harmful effects of MJ use and abuse. Besides, if you're concerned about users the IMO better way to address the problem of people getting harmed for using MJ or its derivatives is public information, better information, informed consumers, informed parents. I don't see how keeping it underground and criminalizing the sale and use works BETTER than what we did with tobacco, which has always been legal and has been quickly going out of style in the U.S. because of a sustained information campaign about the dangers of smoking, and what we've done in some ways with alcohol, especially the dangers of driving drunk.
So I don't know what your suggestion is here. Keep it illegal? Legalize it but better education? Legalize it but regulate it heavily?