The liquor and gambling industries thrive at our well-documented social cost. Their expensively contrived advertising imagery depicts both as part of a vibrant and happy social life - which of course they are; plenty of people gain great pleasure and do minimal harm to themselves or anyone else by participating in such pursuits.
But the point is that we do not want for opportunity to do so. The proposed expansion is driven not by Auckland's need but SkyCity's. And the mountain of evidence of the social harm caused by such entry-level gambling as the pokies provide argues very strongly against the wisdom of accommodating them.
This social harm should, of course, be seen as intolerable even if we get a free convention centre in return, because we are trading human misery for putative economic prosperity - a devil's bargain if ever there were one. But if there is a need for a much larger convention capacity in Auckland - and the global economic outlook can hardly make the most isolated country on earth a natural choice for convention organisers - surely the most logical way to provide it would be by expansion of the Aotea Centre, which will be virtually slaughtered by the arrival of a newer, larger venue.
Key has not persuaded the public of the case for the pokies-for-building deal. Indeed he has not really tried to, apart from making off-the-cuff remarks to journalists about the jobs and wealth it would certainly create.
But under the circumstances, it seems apt to throw back at him a version of the line with which he taunted Phil Goff on the campaign trail: show us the money.
More important, the evidence now coming to light makes it plain that Key's behind-the-scenes discussions with SkyCity were at least extremely exceptionable and almost certainly entirely improper. It can be very good for the country to have a Prime Minister who is also Minister of Tourism and who can move in the upper echelons of the business and finance communities where he once worked. But it is an extremely far cry from that to have him sealing deals while a competitive process is still in train, which is what is being suggested.
The whole matter could do with the disinfectant of a thorough airing. It is well beyond the point that the PM can smile and shrug off public concern.