I think you are taking those links as an overly important part of Hanson's argument. His point is that if we consider where life originated without any a prior

I think you are taking those links as an overly important part of Hanson's argument. His point is that if we consider where life originated without any a priori assumptions, Mars could be viewed (based on some existing theories) as a more likely place of origin than Earth. He's simply peeling back some of the existing (and often immovable) theoretical layers that filter our perception of the underlying reality and asking whether any of those layers might be reasonably discarded. In a way this is the same point made by Kuhn about the calcification and cultural embeddedness of scientific authority. He then notes that we humans seem to have a bias in which we eagerly rule out explanations that turn out to be true, and wonders how we might overcome this. He proposes a prediction market mechanism that would allow for probability-weighted odds-making while also allowing for profits to be extracted by those whose knowledge is not widely shared; in effect an incentive for structured investigative behavior toward answering a series of deep and related questions. It's not that Hanson believes archaeologists lack humility, just that the questions that are considered most interesting and the analytical approaches that are the most culturally rewarded may result in a landscape that prevents us from understanding an (obvious?) deeper truth. I think that to appreciate Hanson's method of argument you must adopt a view of science as a collection of imperfect models and humans as irrational monkeys playing with the models and often overlooking valuable inferences and insights. Put another way, under what circumstances would one of Hanson's proposed prediction markets fail to achieve equilibrium (liquidity)? Your analysis would suggest that you would bet $0.99p or $0.01p on any of the contracts and happily await reality to prove Hanson foolish. That's the point of such markets, however. Hanson would love to be shown that one of the markets he suggests had that quality, as the price would be valuable information about the robustness of the underlying constructs.