Nicotine, caffeine, refined sugar, alcohol. All of these drugs can be addictive yet none will kill you in moderate amounts. However, a proportion of humans will become addicted to any of those and won't be able to control their use, such is the nature of addiction (I am one of those addicts, with regards to nicotine, although I only smoke socially these days, not continuously like I used to, I will always be an addict and can slip up quite easily). Alcohol is by far the most destructive - and the only one that can kill if withdrawal isn't managed - I am thankful that is not my poison. Nicotine is the most addictive - but even here, not everyone who tries it becomes addicted to it.
Do I want to live an a world where everything is prohibited because a portion of users will have an issue with the substance? Fuck no! What about young people who will and SHOULD want to have a few years of experimenting and trying different things? What we need is education, not prohibition. Educate about healthy eating, healthy alcohol consumption. You want to smoke? Fine, but it'll be expensive, it ought to be something you do occasionally, not all the time. Same with alcohol and sugary treats/fatty foods.
I'm pretty sure unhealthy lifestyles and diet kill as many people as smoking (probably more?). So, are they going to ban unhealthy foods and force everyone to exercise? Where does it stop!?