I promise I'll leave the topic alone after this post, but it occurs to me that, if we make the assumption McArdle really was looking for answers on this subject rather than pushing a party line, then the process here is revealing. Having spent a few minutes putting together a badly considered post questionable research, McArdle spends some time soaking in the bile of those that disagree with her. She then takes the most ridiculous and unsavoury arguments presented and claims them as proof that what she suspected was right.
Her process to conclusion works as follows, then. Write something stupid, then use the stupid that it generates in response to argue that the case is closed (because as we all know, people who claim to be academics who comment on unconvincing blog posts = a representative academic sample). I mention this because it's a very common method of self-reinforcement, and so it should be noted and objected to whenever it arises.