Louie, I think you're mischaracterizing these posts and their implications. The argument is much closer to "extraordinary claims require extraordinary evidence" than it is to "extraordinary claims should simply be disregarded." And I have outlined (in the conversation with SIAI) ways in which I believe SIAI could generate the evidence needed for me to put greater weight on its claims.

I wrote more in my comment followup on the first post about why an aversion to arguments that seem similar to "Pascal's Mugging" does not entail an aversion to supporting x-risk charities. (As mentioned in that comment, it appears that important SIAI staff share such an aversion, whether or not they agree with my formal defense of it.)

I also think the message of these posts is consistent with the best available models of how the world works - it isn't just about trying to set incentives. That's probably a conversation for another time - there seems to be a lot of confusion on these posts (especially the second) and I will probably post some clarification at a later date.