I'm not totally against government regulating vice, I do wish it was done at a local level so that in the spirit of federalization we can see what works and what doesn't in small experiments before other states would voluntarily adopt it. NZ is a small state so not too many people will be impacted.
I do think in an environment where the government is responsible for health outcomes it makes sense to pass mitigating regulation to minimize the costs of health outcomes. Though I do worry we may end up with mandatory exercise and a Canadian style widely encouraged assisted suicide model.