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:
In other words, prizing discourse without limitations (I tried to find a convenient analogy for said limitations and failed. Fenders? Safety belts?) will result in an environment in which people are more comfortable speaking the more social privilege they hold.
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.
There is no such thing as open discourse any more than there can ever be such a thing as a 'free' market. Implicit and explicit power and privilege always prevent both. People trying to create workarounds for this fact strikes me as a good thing.
If I register an anonymous account on a forum than power doesn't prevent me from speaking. I might get disapproval, I might even get banned but I don't have to expect repercussion for my daily life from speaking my mind.
It's not like a face to face conversation where you have serious consequences for speaking against power.