The opening sentence is wrong, as well as Gizmodo’s title. If you read the manifesto in full, you should recognize it opposed Google’s diversity initiative. That is vastly different from the label ‘anti-diversity’. Do not let passion blind your reason. If you do, you fall exactly into the stereotypes that the manifesto describes.
By the way, the author of the manifesto is by no way a sexist or judging by stereotypes. He clearly stated (emphasis is mine):
I’m simply stating that the distribution of preferences and abilities of men and women differ in part due to biological causes and that these differences may explain why we don’t see equal representation of women in tech and leadership. Many of these differences are small and there’s significant overlap between men and women, so you can’t say anything about an individual given these population level distributions.
… treat people as individuals, not as just another member of their group (tribalism).