They aren't necessarily saying the temp won't rise or that the climate and landscape and bioscape won't change. It's possible to simply not have a problem with any of that.
Climate change debate is more about agreeing on a goal than agreeing on a fact or an outcome.
A whole bunch of people would not bother betting on either outcome, and so the bets have no influence on their actions.
The regulatory stopgap seems inelegant too. Like the whole point of the article is to try to get a system to self regulate through correct alignment of incentives. Well that part indicates an imcomplete system then, since that's not an incentive, nor even an elegant equilibrium-based governor mechanism, it's a plain manual control.
Well since they didn't say what the regulatory measure would be I suppose that could be something elegant, but I think it's too central to the whole idea to leave as a handwave. That's like the step 2 ??? between socks and profit.