"...there are many areas where I just would not expect 50/50 anyway. "
Sure, and the emphasis on 50/50 is a little misleading anyway, because random sampling doesn't work like that. But the point I was making is that you don't have to "not expect 50/50" to be just a little, shall we say, "surprised" when the actual split in question is 80% men to 20% women. At that point you should surely start questioning if, at least, the biological differences are being heavily exaggerated.
I think at one point the writer also says that, "We need to stop assuming that gender gaps imply sexism," and that's something else I agree with, in as much as the gender gap can have more to do with how many men and women are applying. But then the question still is: "why aren't women applying in the numbers needed that would lead naturally to equal representation?" And, if they aren't applying because they generally aren't interested, why are they not interested? What is it about the job, or the environment, or whatever, that is putting them off?
There's just so many factors at play, that to reduce things to "oh, it's just biological and there is therefore nothing you can do about it" is clearly simplistic, given what is a *huge* disparity in some instances, and probably wrong a lot of the time too. Perhaps there will come a day when there is nothing left to explain the difference but the innate, but I don't think anyone can seriously believe we are there yet.