Generalizations are, by nature, inaccurate because they don't allow for exceptions.
So, in the interest of not generalizing the entire WoW population, some males are idiots who think "all women" are this or that (ie, emotional, untrustworthy, lousy tacticians, always social, etc), when all women can only be generalized one way: individual. Every woman is different, and you cannot make accurate assumptions on us all based on the ones you've met.
I get emotional sometimes. I'm not fond of prepping my own gear (my husband does it). I "squee!" over cute things like kittens and pink and The Sims. I'm a competent player, mostly casual, can remember a fight after one successful run, and possess above average intelligence.
If I thought for one second that my guild assumed I was only an emotional, girly, chattering kitten-addict, I would gquit. My guild shows enough respect for its women not to toss us into generalized categories or lump us all together like a plant genus: homosapian femininus.
What bugs me about the whole thing, though, isn't that stupid boys make stupid assumptions. If they're idiots, it will show, no reason to be surprised.
The part that gets me is when women sit there and take it. Why do some women not call out their guild leaders when someone treats them differently based on gender, why don't they demand the guild prove that it cares enough to squash sexism in its flacid bud? Why don't we report offenders?
Is it laziness? Is it misinformation or the belief that we can't do anything if the guild leaders won't, that we have no power? That our guild shouldn't have to stand up for us because it's just a game? Is it the fear that reacting harshly will fulfill the prophecy that we're all "emotional"?
I'm not officially a feminist, but my mother was raised by her single mom and a boatload of aunties. My mom is the kind of woman I'd be afraid of if I wasn't her kid -- she's friendly until it hurts (either her or the people around her), hospitable to the extreme, and the scariest freaking woman in the world when she's mad (even God couldn't have helped my high school administrators when the gym teacher let my brother get hit in the head with basketballs).
I was raised by that woman. And she instilled in me the unwavering belief that you must respect yourself enough to get out of a situation where others don't respect you.
I don't care if your best friend is the guild leader, or if you are the guild leader. If your guild, your officers, your members won't stand up and say "We don't want people here who treat women differently based on gender," then you need a new guild.
No drop is as legendary as self-respect.