Except alcohol already has a delivery mechanism that's probably the healthiest option, whereas smoking to get nicotine is inherently anti-social and harms others with secondhand smoke. Anyone in NZ who wants to be addicted to nicotine can still dose using a vape, which doesn't have the same downsides for others.
It might be more comparable if NZ were banning some more dangerous way of getting drunk that also gave bystanders cancer.