You're right. There's intoxicating drugs and then there are machines designed specifically to take human life. They both can cause harm, but can also have practical or recreational uses.

Why, when it comes to mitigating the risks, you want total prohibition of one and not the other? Murder, suicide, and deadly accidents are worth the benefits gun give us as a society? Why? I want to hear your reasoning.

I know you wont give it because I think you're smart enough to see what I'm doing. As soon as you say something like "Because adults should have the right to buy a gun and if they abuse that right then they should be punished, it doesn't mean we should outlaw guns because that wouldn't solve the problems that occur with guns" you'll realize that it applies exactly the same to cannabis. 

Just because you personally approve of gun use and disapprove of cannabis use doesn't give you permission to be logically inconsistent. Have your preferences but don't pretend you're not biased.