I think the whole point of the article (which seems to have gone over your head) is that men and women have somewhat different abilities/interests and tend to excel at different things. 

Which is not to say that "women can't do math" (some probably can't, of course). But in general you would expect somewhat more women would be in some fields and somewhat more men in other fields. 

So aside from the issue of Google summarily firing someone for expressing doubts about the wisdom of the company's diversity policy (when, supposedly, the company welcomed a 'diversity' of employee opinions), the other question is whether the policy realistic or not.