Technical the machines are being used, allegedly (eye to MNHQ), to money launder. You can pay a huge volume of cash in, lose a small proportion, then cash out with a receipt showing "winnings figure" which then explains where you got it from, without saying how much you originally entered. There's no current way of dealing with that. There are also worries about levels of criminality associated with addicted gamblers, and the machines are infinitely more addictive than traditional forms - there's no real comparison to the National Lottery because even scratch cards weren't dealing in the sums of money the machines do, and people had to buy them from someone prior to online availability (and even now, they can't begin to lose hundreds of pounds a minute on them or anything like it) so it wasn't just them and a machine (though it arguably made gambling more socially acceptable, agreed.) Those machines are hugely problematic, and the tax created may not be enough to compensate for the social costs.
I don't really want to get too much into the whole gambling ethics issue because it's only relevant here inasmuch as any increased focus will be getting management at the firms jumpy, so it's a distraction. But senior management at one very large betting firm have had their pay this year linked not solely to profits, as usual... but also to their ability to demonstrate action taken on "social responsibility". (Which is frankly rather entertaining, given their industry's whole business model and the presumable impossibility of proving more than window-dressing, but perhaps indicates the way the wind is blowing within the industry ranks.)
Ironically, the form of gambling these ads aim at is the "small flutter" which isn't that problematic, or at least not comparatively. But they're so abhorrent in terms of attitude that it may draw unwanted attention from people other than the late adolescent males the campaign is actually aimed at. (Which is, really, admittedly, rather clever on its own terms. The industry are obsessive about regulatory compliance in terms of age, and can't afford to risk ever being seen as targeting young people, so this ad is defensibly targeting people old enough to legally gamble, but at the bottom end of that age range - late teens and early 20s men.) I can see why they've done it. I just think they've been tone deaf in terms of what most of the population will stomach, and the current climate on gambling more generally. And in turn, targeting the reaction in a direction the industry really don't want pressured against them is all we can do. Which is, at least, better than nothing, no? I doubt their target market are big Mumsnet browsers, any more than the average MN will use those machines. But we do vote - as Brown and Cameron both understood at the last election.