When the Productivity Commission reported in 1999 that one in every five poker machines in the world was found in Australia, and they were sucking the life out of their mostly impoverished human playmates, even John Howard said he was ''ashamed'', and Mr Howard was certainly not in the habit of tossing that word around.

Kevin Rudd was so worried about gambling nearly a decade later that he activated ''Code Red'' on the Rudd Response to Threat Scale: another inquiry by the Productivity Commission.

Julia Gillard was similarly convinced of gambling's evil. So much so, in fact, that she signed a deal with Andrew Wilkie to inflict a major blow on gambling; a promise she fearlessly kept, right up until the point at which the possibility that evil might strike back in certain key electorates prompted a brisk abandonment of principle.

Everybody pretty much knows by now that gaming operators are vampiric parasites who thrive on human misery, and their victims are pitiable beings who would sell their granny for another go on the Black Rhino.

But what happens when gambling is used for good, not evil?

Anti-pokies activists are much less troubled by the work of David Walsh, the Tasmanian squillionaire who has sunk $180 million from a wildly successful gambling career into his Museum of Old and New Art in Hobart.

Mr Walsh is pretty much unembarrassable, either on his wealth (''I've done nothing for the money,'' he told The Monthly), his choice of art or the fact that he has named his museum after a Craig McLachlan song.

And the museum's been a hit.

But the colour of Mr Walsh's money is really not all that different from the pokie barons', is it?

Gambling, in all of the forms I can think of, is about the windfalls of a few, bankrolled by the losses of a multitude.

For every David Walsh, winning lavishly on Keno or the horses, there needs to be a million or so losers trudging home with scorch marks in their pockets, otherwise the system does not work.

Anti-gambling activists such as Bob Brown and Andrew Wilkie, however, are right in Walsh's corner, as he confronts the Australian Tax Office's demands for nearly $40 million in back taxes.

This may be the first recorded instance of the former Greens leader opposing a tax on the wealthy. And one suspects Walsh might not have enjoyed such enthusiastic support had he chosen to sink his millions into a wood-chipping theme park rather than an achingly cool ''temple to secularism'', whose exhibits constitute extreme provocation to local prudes and Christians.

God, incidentally, is another individual thought more or less to be in the anti-gambling camp. While the Bible is frustratingly skimpy on specific divine pronouncements regarding Queen of the Nile or Powerball, there are plenty of clues scattered about.

The bit where the soldiers cast lots for Jesus's clothes after crucifying him, for instance; not a good sign for the industry. ''He that tilleth his land shall be satisfied with bread,'' Proverbs says. It doesn't add, ''And he that winneth the box trifecta shall be crushed by his own Chris Ofili painting,'' but you can pretty much see where it's heading.

You know how the Bible works, though; you quote the bits you like and ignore the bits you don't. And the church itself has averted its eyes from Proverbs long enough to establish profitable bingo halls, and Catholic Clubs at which poker machines extract regular tithes from the faithful. Morally speaking, gambling is not always a straightforward affair.

And everyone loves a punter who beats the system, even when in beating the system, he perpetuates it.

One of the cheeriest stories from Wimbledon last week was the news that Oxfam had made £100,000 ($152,000) from a betting slip bequeathed by a long-dead punter who had had the foresight, back in 2003, to stick a grand and a half on Roger Federer to win seven Wimbledon titles.

And a rich man who blows other people's cash on a pirate's cave of art treasures for Tasmania cannot help but be a sympathetic figure, however ill-gotten his gains. Much as the understandable human resentment felt when exchanging one's own hard-earned for Microsoft Word is substantially mitigated by the knowledge that Bill Gates is out there spending at least some of it on eliminating polio.

In effect, what David Walsh has done is create a small hypothecated tax system all to himself, in which money from gaming operators and small-time losers has been harvested and converted into an art gallery.

And if you think that's bad, just remember it could have been worse - the government could have built the gallery.

Annabel Crabb writes for ABC Online's The Drum, at abc.net.au /thedrum and tweets as @annabelcrabb.