From the conclusion: "One thing is certain: Google is not paying Mozilla a billion dollars out of the kindness of their hearts. Doing so would be irresponsible to their shareholders. Again, they’re paying all that money to a competitor."
People never seem to understand why Google builds Chrome no matter how many times I try to pound it into their heads. It's very simple: the primary goal of Chrome is to make the web advance as much and as quickly as possible. That's it. It's completely irrelevant to this goal whether Chrome actually gains tons of users or whether instead the web advances because the other browser vendors step up their game and produce far better browsers. Either way the web gets better. Job done. The end.
So it's very easy to see why Google would be willing to fund Mozilla: Like Google, Mozilla is clearly committed to the betterment of the web, and they're spending their resources to make a great, open-source web browser. Chrome is not all things to all people; Firefox is an important product because it can be a different product with different design decisions and serve different users well. Mozilla's commitment to advancing the web is why I was hired at Google explicitly to work on Firefox before we built Chrome: Google was interested enough in seeing Firefox succeed to commit engineering resources to it, and we only shifted to building Chrome when we thought we might be able to cause even greater increases in the rate at which the web advanced.
It's not hard to understand the roots of this strategy. Google succeeds (and makes money) when the web succeeds and people use it more to do everything they need to do. Because of this Chrome doesn't need to be a Microsoft Office, a direct money-maker, nor does it even need to directly feed users to Google. Just making the web more capable is enough.
So sure, Google gets some direct value out of Firefox users searching with Google by default. I'm not contesting that. But the whole "You're funding a competitor!!!" angle is misguided. Google is funding a partner. We and Mozilla are working together to make the web awesome.