To add to andylei's comment, I've pasted my own reply from Randal Olson's follow-up article (http://www.randalolson.com/2014/06/15/the-double-edged-sword...):

I agree that men and women most likely do make different career choices. Yet, choices aren't made in a vacuum.

We have a culture that reinforces ideas of innate gender roles. Little boys are told every day that they need to be tough when they get hurt, that they shouldn't be a crybaby. Little girls are told that they can't handle rough housing, that math is too hard for them. Little girls are told they should be friendly and "nice", that they should play well with others and build communities, mediate between friends. Little boys are told that they need to be responsible and be able to take care of people.

These attitudes are shifting. I am glad that they are shifting. When we tell boys and men that they have to be tough, we create a culture that makes it harder for men who are struggling with things things like depression and addiction to seek help or even admit that they have a problem to their friends. When we tell girls and women that they are weaker and less capable in certain fields, they begin to internalize those values. They begin to believe that they really aren't cut out for it, that it is too hard.

There is a lot more that can be said on this topic, and to some degree it can be debated about just how "innately" different men and women are. However, the problem is that this viewpoint considers things in the aggregate. In life, you are an individual. That means that you should be able to deviate from what "men" are like or what "women" are like just because that is the way you are. So why do we tell little girls and little boys that they should be one way? If there is a difference between men and women, then we should be able to just let that difference exist, without trying to shape people to fit into our view of what those differences might be.

In general, as humans, we like to categorize things. This has been an immensely useful skill. It underlies most of our science and most of understanding of the world. It is fundamental to computer science since it allows us to do things like DRY (Don't Repeat Yourself) and OO (Object-oriented). The problem is that when we see fields that are largely male dominated or largely female dominated, many people draw conclusions about what men and women are like. Relatively few stop to consider what societal pressures might have shaped the decisions of the people who enter these fields. They chalk it up to innate differences between men and women. And then they question people who don't fit into those molds that they have created in their own minds.

Think back to those male nurses and female coders that we keep talking about. They don't seem to fit into a mindset that says that men prefer to do things like code and women prefer to do things like caregiving. People express surprise and sometimes even censure because these people don't fit. If we push men out of nursing, we have an even more female-dominated nursing population. We reinforce the idea that women are caregivers. Because why else would so many nurses be women? We've created a cycle. This is why I get concerned when the fields are so disproportionate. It's not just that men and women are making different choices. It's that we have created attitudes that reinforce those choices and make it harder for people to make different choices. It makes it harder for people to succeed when they make a choice that strays from our mental guidelines.

Again, sorry for the wall of text. Have another kitten: http://imgur.com/gallery/KWDadE1