Has joining actually been made harder and less pleasant for ~54% of the population? Has joining been made harder and less pleasant for ~54% of the population as a result of that ~54%'s membership in those two demographic groups?
There is no inherent quality of being female that would make one be viscerally repulsed by the use of the term 'sluttiness'. Apophemi cites that as an example of a term the use of which makes joining harder and less pleasant for... well, 55% of the population, as a direct result of their membership in those demographic groups:
If by “sluttiness” r-you mean “sexual promiscuity”, what is gained by using a gender-targeted insult that is likely to make a significant portion (i.e. women and/or queer people, who together are like… 55% of the world at least) of r-your potential audience uncomfortable and less likely to engage with r-your argument?
I hope it's obvious that "women and/or queer people" aren't the operative groups here. I certainly haven't noticed any inherent property of my not being straight that makes me necessarily uncomfortable with the use of the word "sluttiness" and less likely to engage with arguments that use it, and I've heard women use the word in the exact same sense the reactionaries Yvain was arguing against in that post used it.
After rectifying the names, it emerges that the operative group is a political identity -- one that may be (and probably is) more likely to contain a higher percentage of those demographics than the population at large, but one that is neither identical to nor inherent in those demographics.
"I speak for the entirety of this demographic" is a really suspicious thing for a human to say -- triply so when it's about something politically charged.
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.