The PM has admitted he has never smoked the stuff, which for a man his age is just sad. In fact, it may be a large part of his problem.
But the lack of direct experience of a subject has never stopped anyone having strong opinions about it. To pick one example of many ministerial mismatches, Simon Bridges, a man with an apparent mania for motorways, has a portfolio that includes responsibility for public transport, which he gives every appearance of wanting to see banned.
In years to come, after wider reform has been in place for some time, people will look back at incidents such as the January conviction of terminally ill Paul Dempster, sentenced in Invercargill District Court to supervision for having a few plants for his own use, and wonder that they were ever allowed to happen.
Much wider marijuana law reform is urgently needed for many reasons, not least the effect its prohibition has on fuelling a P epidemic.
Anyone who took the trouble to listen to what Hone Harawira had to say on that issue - beyond attention-seeking and getting headlines about capital punishment for Chinese drug dealers - would have heard how people in Northland who can't get marijuana are having P offered to them as a cheap alternative, with ghastly consequences.
"But why do they have to have drugs at all?" Among other explanations, for the same reason you need that glass of wine. And you may not have the added inducement of a life in a cycle of poverty and abuse such as can be found in so many communities where P has hold.
Ironically, the proposed law change will almost inevitably create a new black market in repurposed medical marijuana.
We already have a black market in prescribed opioids, which are widely sold by cancer patients to addicts. It's just a short step from such voluntary trading to sales made under duress. If marijuana was more widely available there would be no risk of this.
Yes, this law will be good for seriously ill people who will no longer have to add the vicissitudes of sourcing their weed to the stresses they are already enduring. But it is a wasted opportunity.
Far from opening any floodgates it will delay wider reform. Any new attempt to liberalise the laws in the interest of reducing other crime and more dangerous drug use is unlikely to get a hearing for a long time, on the grounds that "Oh we did marijuana just a while ago".