>In other words, you missed the point entirely: this is more continued evidence-free speculation,
Actually it's not evidence-free, it is a simple application of evolutionary theory. The "point" of the OP's post, as he stated directly, was that there was no "evidence" supporting the theory that observed gender difference are biologically caused. Pointing out that different brain structures between male and females means different behavior that would necessarily be observable directly refutes that point.
> complete with hand-wave theorization that there has been a gender-based task division matching the dominant Western religious-driven socialization for hundreds of thousands of years
Again, application of theory. Tens of thousands of years ago, our low level of technological development necessitated specialization. A family back then would have no other option than division of tasks based on gender because, for example, someone had to stay close to camp and care for children and someone had to go out on the physically more demanding food gathering tasks. Which genders do you think would do what? If you can visualize some way it would be more efficient for the males to constant shuttle back to camp from a hunting trip to tend the baby instead of just staying out as the job required, or for the females to do the hunting with their significantly less muscular bodies and the males to tend to the infants at camp without breasts, then by all means, do. Otherwise its a fairly obvious conclusion to be drawn from simple establish facts (women are statistically less muscular, men don't have breasts.)
>It's highly likely that there are measurable differences in the capabilities between male and female brains but neuroscience is very far from being able to explain anything high-level enough to start speculating about the complex skills relevant to these discussions
Who said anything about "high-level" being the criteria? You seemed to have pulled that qualification out of thin air.
>The other major confound is that many people rely on MRI data to support claimed differences and even assuming that the technology is precise enough and the relevant brain structures well understood enough
That misses the point, we don't have to understand the brain structure to know that a physiological difference in the brain will cause behavior differences, it's functionally necessary. You don't have different brain structures without an equivalent differences in behavior. It's also not important that we can't detect less significant differences in brain physiology because MRIs aren't more precise than they are; they have a specific scanning resolution and can therefore detect features reliably that are above the minimum resolving dimensions of the MRI. Those are the features being talked about here.
And as far as the assertion that some of these brain differences are caused by nurture, there are simply some gender based brain differences that are too consistent and develop too early to be explained by anything as variable as culture or upbringing.
>Finally, "Evolution put those differences in brain structure for a reason" demonstrates a fundamental misunderstanding of the mechanism: there are many, many examples of things which exist by accident
Actually, that is a fundamental misunderstand of evolutionary mechanisms, it is essentially impossible to have reliably observed features in a species that are not caused by evolutionary benefit. A side effect feature which you are proposing is a moot point, because side effect features are still connected to some other distinct feature that is beneficial evolutionary, and if the side effect feature is only observed in one gender then the primary-beneficial feature which causes it is still also in one gender only, and we are still in a situation where one gender is different from another via physiological brain differences.