I think a lot of it has to do with image and publicity. I feel dfing smokers is wrong and too harsh.
But I think the"society" wanted to up the stakes to give people a bigger incentive.
Masturbation is usually in private and less likely to "bring reproach" on the organization.
I think a better comparison is withhow they handle pedophiles.
It seems like they show more mercy to a child molester than to a smoker.