The purpose wasn't to prove that Google is using its diversity programs for nefarious purposes; only to raise the question that Google's diversity aims might be

The purpose wasn't to prove that Google is using its diversity programs for nefarious purposes; only to raise the question that Google's diversity aims might be misguided and even potentially harmful per their stated goals. He supports his argument by pointing to studies that suggest men and women may be differently interested, in which case we shouldn't expect 50/50 distribution. Perhaps whether or not Google's diversity programs are lowering the bar is the more important question; it's also one he likely wasn't well-positioned to tackle (it requires a lot more resources to prove/disprove bar-lowering compared to writing a memo to express a concern).