The author accused Google of discriminatory hiring practices and "hiring practices which can effectively lower the bar for 'diversity' candidates" (under the subhead, "The harm of Google biases"). Just because he couched his claims in a boring, vague manifesto doesn't mean he didn't imply something that impugns the qualifications of his coworkers.
https://www.documentcloud.org/documents/3914586-Googles-Ideo...