This kind of thing seriously aggravates me. Let me begin by acknowledging that yes, I have found many female characters written by male authors to be unconvincing and/or stereotypical. And yes, I am less likely to find this the case with male characters written by female authors. I don't know if that's because women have a more accurate vision of men than vice versa (it is certainly true that the media affords a lot more exposure to the latter) or because I'm less likely to notice a bad portrayal of a male character.
But to call that possible trend deterministic -- ALL men write worse female characters than ALL women -- is such ridiculous hyperbole that it raises every hackle I possess. Will whoever is teaching people to speak and write 'with conviction by avoiding qualifiers and making sweeping generalizations' PLEASE STOP?
This kind of gender-based nonsense is pernicious, not the least because women do not become magically immune to sexism merely by being women. This is our culture: we are all soaking in it. We are all brainwashed by its assumptions. Women may have more incentive to resist and more inside knowledge on why it's wrong, but that doesn't mean that every woman is free of all gender stereotyping.
In fact, the linked article is perpetuating gender roles. "You are male so you can't write half the human race". I don't know what the point to doing this is. Does Diaz like gender roles and wants them to continue and be strengthened? Because that's the effect of making claims like Diaz's: make sure we can never escape gender roles. Your life and skills must always be defined by your gender. That the gender sterotypes Diaz offers are unfavorable to men and favorable to women does not make them any less of a role based on gender alone. Talking about how one gender does things better than the other is how we got INTO this mess. It is not the way OUT.
I also have to wonder if Diaz thinks women are over-represented in fiction and we need more men in books? Because telling half the populations "your female characters do now and always will suck because you are male" is NOT the way to get them to include more female characters in their work. That is pretty much telling them "write people just like yourself and no one else because your gender makes you physically and mentally incapable of every understanding anyone else". This is not my idea of productive.
I want to say right here: if John Green, Brandon Sanderson, howardtayler, the_gneech, jimhines* can't write female characters, neither can I. Being female did not endow me with mystical powers of writing convincing characters of either gender that mere males cannot possess. I'm really quite sure of this. If their female characters, many of which I've become quite enamored with, are all flat and underdeveloped, then every one of mine, male or female, is at least as bad or worse. If they don't know what they're doing, I don't even know how I'm supposed to tell when someone does.
* This is an "off the top of my head who can I think of" list, so it ended up as some of the male authors I follow on either LJ or Twitter. There are LOTS MORE.