This is probably not true.for example:
People know smoking kills. The tabacco industry even popularized stories about sad COPD patients that were dying in the hospital and still wouldnt quit smoking.
"Its that good!"
"It's so nice! Even when you know it kills you, you still dont want to stop! Not to mention! Quiting is hard! Real hard! Dont try to quit. You will only suffer."
Smoking tobacco was subject to well over a century of well-funded marketing, anti-science efforts to hide adverse effects, and even claims of being good for your health. I don't think there's a Joe Camel for heroin, and if there is, some poor homeless bastard shooting up isn't it.
Tobacco use - despite its visibility and despite being extremely addictive - went down a lot. Legal and normal are NOT the same thing. The biggest problems arise when normal is illegal as it undermines the law and maintains delusions about what is going on in reality.
In the EU 1 in 4 adults smoke tobacco daily[1]. It sounds pretty normal to me. In practice when I commute daily, I always need to hold my breath several times each way, just to avoid the stench.
It's like if we presented corpses of dead drivers on the main streets – I bet it'd greatly lower overspeeding and drunk driving