Reason behind my topic

There are many debates about legalizing marijuana. Some people say it is to help cancer patients and other say that its for " unlawful criminal teenagers who dont have any respect" but for the ones who dont understand how to use the medicine they are prescribed correctly lear this  The reason people believe marijuana should be legalized because there has never been a reporting of anyone dying of marijuana. But I hear plenty of reportings of people dying of alcohol poisoning or cancer from cigarettes because of the chemicals put in them. I say that if the government can let people decide whether to drink alcohol or smoke cigarettes that kill them, then why cant they decide to smoke marijuana on their own?