I'm not trying to be political here, and I don't think this is about LW or rationality, at all. If that observation is to have a point, I'd suggest an entirely different one:
It isn't just that scripture, constitutions and classics of literature were mostly written by men. Or that men just write more, in science, in journalism, in genre fiction etc. and almost all quotes are from written, rather than spoken expression... That's all just the "being quoted" side of it. But the quoter participates, and I think quoters are usually male too. Even The Simpsons get quoted mostly by guys rather than than girls, at least around me...
It's clear to me how quotation as a male form of communication would mean that women quote less, which you could check by comparing the usernames of quoters to the post-weighted sex distriubtion on LW. It's not as clear to me how it would mean women get quoted less- that would have to be either because of my first or second explanations. (I'm counting "men quote men more frequently than they quote women, and men dominate LW" as part of my second point.)
Here is the 2013 edition of the Best of Rationality Quotes collection. (Here is last year's.)
Best of Rationality Quotes 2013 (400kB page, 350 quotes)
and Best of Rationality Quotes 2009-2013 (1600kB page, 1490 quotes)
The page was built by a short script (source code here) from all the LW Rationality Quotes threads so far. (We had such a thread each month since April 2009.) The script collects all comments with karma score 10 or more, and sorts them by score. Replies are not collected, only top-level comments.
As is now usual, I provide various statistics and top-lists based on the data. (Source code for these is also at the above link, see the README.) I added these as comments to the post: