No matter how the rest of the essay is, this honestly doesn't mean jack and insults the intelligence of his critics, no matter how off-the-mark they were. He goes on to note other, more meaningful statistics, which is great, but this sentence alone is kind of laughable.
edit: the downvote was predictable, although still disappointing. I was simply pointing out that picking your wife as a cofounder should not be used as proof that you are not biased against women. Honestly, PG's argument would be stronger as a whole if he removed that line from the essay.
edited to add: The reason the "look at my black friends" argument is mocked is that in many cases the friends referred to are not friends in the true sense of the word. There's no such distinction possible when talking about a co-founder. One either is or is not a co-founder.
You can also be married and be sexist.
I don't know Paul but I do know that based on this article he's laying out the problem based on what he knows which is start ups. I appreciate him doing this as I get a better insight to the problem from someone that has firsthand, "in the field" knowledge. I also got some great takeaway action items that I can apply for my own kids. So, thanks for that.
The fact that investors make or lose money based on their beliefs does provide one source of pressure to be rational, but it's not a guarantee.
In my professional life, of the the managers working for me was formally accused of racist conduct by an employee he supervised. The core argument was that he was unpleasant and unfair to him based on his race. A major part of his defense was his family (his wife happened to be of the same race), his children, and the extensive work that he did in that community mentoring people.
Bias is a state of mind. Facts/statistics alone do not tell the story.