> This is like forcing motor cycle riders to wear helmets.

Maybe this is a petty, pointless distinction, but I think they're quite different. Singapore banned the ads, not the actual consumption. Not wearing a helmet chiefly harms yourself, and it's hard to argue that it's immoral. Encouraging others not to wear a helmet, though... that seems pretty objectionable, just like ads for tobacco etc.

(Of course there are plenty of caveats needed to avoid a slippery slope, like drawing a distinction between advertisements and opinion pieces saying "helmets are bad".)