*should* be and *will* be, are two different things. The problem is, we are dealing with many unknowns right now. There is no real certainty about what the outcome of legalization is. There are guesses based on what other countries have done. We are a country that has a real problem with binge culture.
I'll be exceptionally surprised if the final price of legal weed in NZ is $10 a gram. I'll also be incredibly surprised if the money we "get" from legalizing weed, even covers the cost of compliance and regulation.
I am genuinely torn. I think there are real problems with the existing system, but I have serious doubts if legalization will solve them in any meaningful way. Decriminilzing it would have been a really good first step, but voting no, kicks this current problem probably a long way down the road.