This attitude ("we know what's best; your input is not required") has historically almost always been wrong
Has it really? The cases where it went wrong jump to mind more easily than those where it went right, but I don't know which way the balance tips overall (and I suspect neither do your nor most readers - it's a difficult question!).
For example, in past centuries Europe has seen a great rise in litteracy, and a drop in all kinds of mortality, through the adoption of widespread education, modern medical practices, etc. A lot of this seems to have been driven in a top-down way by bureaucratic governments who considered they were working for The Greater Good Of The Nation, and didn't care that much about the opinion of a bunch of unwashed superstitious hicks.
(Some books on the topic: Seeing Like a State; The Discovery of France ... I haven't read either unfortunately)
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.