Just because there is a clear male preference if the top 10 fantasy series authors, it in absolutely no way infers that women authors remain unread.
Don't think that was meant, so it all seems to be down to the choice of one word: how would it be if Rob had said
"Wow, apparently our forum members (as a whole) don't rate fantasy/fantasies written by women.?"
Or at least rate them enough to make them feature prominently in their collective Top 20's? For what it's worth, my overall impression, based on what I have very quickly looked at in this thread, would be that if we totted up everyone's list to date, the summary would be male-author-heavy. Rob was clearly surprised by that. (He is allowed.)
Based on one word, (and this is the Internet, don't forget!) I think you've read way too much into that, jh. Personally I'm thinking that it may be down to the unintended use of a word. We all do it - me, usually when I'm typing at 2am!
There's lots of extrapolations made above that are not really what we're after here - all that those who take part have to do is list their own 'personal' top list - regardless of gender, good taste, sock size or anything else. It doesn't even have to based on a strict definition of 'what is Fantasy', though we've had that before, too.
Readers all make their own personal choices when they choose what, or what not, to read - some base their choices on the author, others the plot, some the cover, some the background blurb - that's what makes these choices fun. If people want to make such choices part of a mission to enlighten, then there's nothing wrong with that - but I doubt that was the intention of the original poster here, nor the theme of the thread.
Personally the gender thing's not a particular issue for me, as I tend to go on what I like, regardless of who wrote it. Most of the stuff I have read is written by males, but that does rather reflect the market we're in - not saying that that is particularly good or bad, just how it is. To be honest, the name's often the last thing I look at, unless it's an author I've heard of before and want to read more of. And whilst I accept that perhaps there should be more women writing Fantasy (and the same goes for SF too) I'm also going to suggest that it's not my own personal agenda to follow.