The linked article is too long and it is not obvious what exactly its point is. I kept repeating to myself be specific, be specific while reading it.
I believe there was most likely one specific thing that offended the author... and rest of the long unspecific article was simply gathering as many soldiers as possible to the battle -- and judging by the discussion that started here, successfully.
The summary at the end hints that it was a use of word "eugenics" somewhere on LW, or maybe somewhere on some LW fan's blog. Unless that was just a metaphor for something. The author is probably disabled and feels personally threatened by any discussion of the topic, so strongly that they will avoid the whole website if they feel that such discussion would not be banned there. Unless that, too, was a metaphor for something.
(The main lesson for me seems to be this: If you want attention, write an article accusing LW of bad things. LW can't resist this.)
I believe there was most likely one specific thing that offended the author
Why?
What might it have been?
Why wouldn't the author say what it was, if there was such a thing?
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.