People barely have any idea about how to hire a software engineer, much less judge someone's true "ability".
Preferences are also very complicated. People may prefer things very differently given the environment. That quote, along with many others, demonstrates the absolute lack of genuineness on the part of Damore.
Damore throws away any pretense of being objective/scientific when he makes claims like this based on metrics that are hardly measurable. A decent scientist would recognize that making claims with very serious implications like this is greatly irresponsible.