No, the legalization of marijuana doesn't change my opinion regarding the morality of marijuana use. I was never of the belief that marijuana use was immoral.
If anything I believe that it is amoral. It doesn't effect what kind of person you are, anymore that alcohol use or nicotine effect your morality. They are simply substances that effect our physiology in a way that some people find pleasing. I myself have never used marijuana because it is illegal. I am a law abiding citizen and frankly I have a lot to lose by breaking the law for a few moments worth of pleasure. That being said, once it is legal I may try it. Why not? Many of my friends and associates have used marijuana for a long time and have suffered no ill effects. They are, for the most part, happy and productive members of society. I do not believe that marijuana has negatively effected their health or happiness. Many of them will tell you that it has improved their life.
Marijuana is just a plant that contains chemicals that give people an enjoyable feeling, it has no more moral value than a tea leaf or a potato. We are adults, we can make decisions for ourselves regarding our health and our actions.