@Tamerlane it's probably just that women are much more ok with BL in general and can enjoy it. From my perspective BL is something I can't really read, not a homophobe but it does make me quite uncomfortable. On the other side I have no real issues with yuri. I do not specifically go for things that are yuri but if manga/anime is good then I don't mind the yuri being in there. As for women it's probably a similar story but then of course there are those that just want to see some steamy hot men.
@Tamerlane
I've been to a manga/doujin convention/market all of once. Innocent enough name, "Comic City". The general merch booths were fine; pins and keychains and other things some fans had made. The actual manga... I saw 2 that weren't BL. The place was flooded with fujoshi, and I'm guessing they assumed I didn't understand Japanese, since there were a few that had their attention drawn by that interesting looking gaijin, and openly spoke about BL pairing me with Free characters.
Is it all or most women? No. Even in Japan most people aren't hardcore into manga, anime, lns, etc. Of BL fans are they basically all women? Yes. Are there a lot of them? Enough to sustain a large market. What percentage of women who are into weeb stuff are fujoshi? Don't know, would rather keep it that way.