This is a perfect example of spurious thinking, conjecture, fallacious logic and hyperbole. 

Where did anyone, including the author of the google memo say women should be stereotyped or ghettoised?  --> We are talking fundamental biological differences between individuals and statistically relevant trends between genders that may have an impact on career/study and work decisions. 

I for one am not suggesting we forbid anyone from a particular job or field of study, conversely I do not believe that we should force anyone to do a job: that would not be very equitable and smacks of fascism.