You are either mistaken or you are using some arbitrary definition of 'rationality' that I reject. It is not rational to ignore all social implications of a question.

Of the two definitions for rationality, I was going for e-rationality. It can certainly be i-rational to take social implications of a question into account to such a degree that one won't even consider it by fear of consequences. Simply deciding that evolution must be false since the social consequences of believing otherwise would be too unpleasant, for instance. Or you could admit, in the safety of your head, that evolution must be true, but hide this belief because you know what the consequences were. That might be rational both ways. But it is always a failure of e-rationality to refuse to consider a valid question because of social consequences. In the case of communities and not individuals, "to consider" means discussion within the community.

"Taking into account the social consequences" is fine in theory, but it's an easy path towards rationalizing away every argument from every person you don't like. I would be a bit more understanding if the poster in question would have been really abrasive and heaped scorn upon scorn in the opening post. I do agree that the one comment of his that got really voted down was over the line and possibly deserved it. (-8 is a bit overkill, though.) But the opening post was, if not exactly polite, not any harsher than critique in general is. Even if a person has a history of being slightly abrasive, by the very least he merits a hearing when he does compose a non-abrasive criticism. Especially so since there is, in my experience, a certain correlation between (real or perceived) abrasiveness and a resistance to groupthink - either because the person in question just happens to care little for social norms, or because their brain is atypically wired, giving them both weak social skills and a tendency not to fall victim to groupthink.

Nobody is obliged to answer any question on pain of epic rationality fail.

I never said anything about needing to answer any question. But here we have a situation were people are basically saying that the question is good and valid, but they don't like the person who asked it, so in order to slight him there won't be any discussion of it this time around. That's a different story.

And sure, certainly nobody is required to justify their professional goals to anyone who isn't paying their wage. That doesn't necessarily mean it's a good idea to refuse to justify those goals if the question is a good one. I am a SIAI donor, not sure of the exact amount but I think I've donated something in the region of $1500 so far. The feeling that SIAI doesn't really seem to be accomplishing much caused several moments in the past when I've reconsidered whether I should donate or if my money would do more good elsewhere. Recently that worry has abated, but more because of SIAI folks other than Eliezer doing things. If I came across SIAI now and wasn't a donor yet, I can't imagine anything that'd throw up a bigger red flag than a refusal to answer the question "how can I know my money is actually helping the cause you're claiming to advance".

(Tangential, but since we got on the topic... even now, the lack of reporting of what SIAI people actually do remains one of my greatest annoyances with the organization. Anna Salamon posted a great report - as a comment in a discussion thread most potential SIAI donors will never read. My request to have it reposted on the SIAI blog was ignored. This is not the way to attract more donors, people. Not necessarily even the way to keep old ones.)