Yvain suggests that something about the rapid spread of positive affect not obviously tied to any concrete accomplishments may be stimulating a sort of anti-viral memetic defense system.

I think there is merit in this suggestion, or at least along the lines of "there's a (instrumentally rational in at least some circumstances) mimetic immune reaction going on". I've seen a fellow cryonics advocate (who I gather has a substantial amount of business experience) advancing the opinion that Eliezer and SIAI are phony. He's concerned that the whole thing will collapse and make cryonics look bad by association. It's surprising to me because both give me the impression of strong internal consistency and accountability.

There must be some kind of heuristic at work which I haven't developed (either due to personality or experience) which gives some people the feeling that something is fishy. It occurs to me that such heuristics could be useful even with high false positive rates, given that the costs of doing business with a phony usually (in certain business domains at least) outweigh the costs of failing to do business with someone genuine.