My mother told me what causes blindness, and smoking ain't it.
If you do it long enough, you will have smoke, go blind and get hairy palms...
That's exactly the point. As kids we were told masturbation (if I can say words like "kids" on FR) would make us go blind. They lied. So now, when kids realize how they are being lied to about this nonsense, they're more likely to go out and smoke just to piss the authoritarians off. This sort of propaganda and single minded fascism ends up causing more harm than good.