I think you misinterpret Dr Shalizi, and do him a disservice. I think his answer is perfectly reasonable from a bayesian point of view. Basically, I see three common reasons to spend time researching difference between races:
A) People who are genuinely interested in the answer, for pragmatic or intellectual reasons
B) People who are a racist and want to hear a particular answer that fits their preconceived views
C) People who are trying to be controversial/contrarian/want to provoke people
Certainly there are people who are genuinely curious towards the answer, purely for intellectual reasons (A). I am somewhat interested myself. However, the fact of the matter is that many others are interested purely for racist reasons (B). Many racists aren't open in their racism, and as such mask their racism as honest scientific inquiry, making B indistinguishable from A. Showing interest in the subject is therefore Bayesian evidence for B as much as it is for A. Even worse is the fact that everyone knows that everyone realizes this on an intuitive level, which causes most As to shut up for fear of being identified as Bs, while Bs continue what they are doing. This serves to compound the effect. Meanwhile, Cs arise expressly because it is a hot button topic. As a result it is entirely rational to conclude that someone who is constantly yelling about race and inserting the subject into other conversations is more likely to be a racist on average than others. And of course, it's incredibly frustrating if you are an A and just want an honest conversation about the subject, which is now impossible (thanks, politics!).
I think Shalizi deals with this messed up situation admirably: Making clear what he believes while doing everything to avoid sounding controversial or giving fuel to racists. Of course this doesn't work very well because people who call others racist fall into two categories themselves:
D) People who are genuinely worried about the dangerous effects of racist claims.
E) People who realise they can win any argument by default by calling the other a racist
And people who fall under category E do not, of course, care about the truth of the matter in the slightest.
Kind of tempted to write a top-level post about this, now. Hmm...
I think that the fact that there is a debate and that the "good guys" use name-calling instead of scientific arguments, increases also the number of people in the group A.
It's a bit like telling people not to think of an elephant, and then justify it by saying that elephant-haters are most obsessed about elephants, therefore thinking of an elephant is an evidence of being an evil person. Well, as soon as told everyone not to think of an elephant, this stopped being true.
A long blog post explains why the author, a feminist, is not comfortable with the rationalist community despite thinking it is "super cool and interesting". It's directed specifically at Yvain, but it's probably general enough to be of some interest here.
http://apophemi.wordpress.com/2014/01/04/why-im-not-on-the-rationalist-masterlist/
I'm not sure if I can summarize this fairly but the main thrust seems to be that we are overly willing to entertain offensive/taboo/hurtful ideas and this drives off many types of people. Here's a quote:
The author perceives a link between LW type open discourse and danger to minority groups. I'm not sure whether that's true or not. Take race. Many LWers are willing to entertain ideas about the existence and possible importance of average group differences in psychological traits. So, maybe LWers are racists. But they're racists who continually obsess over optimizing their philanthropic contributions to African charities. So, maybe not racists in a dangerous way?
An overly rosy view, perhaps, and I don't want to deny the reality of the blogger's experience. Clearly, the person is intelligent and attracted to some aspects of LW discourse while turned off by other aspects.