On the other hand, Eich probably didn't make such utilitarian calculation, and followed "do not lie" deontology instead. Pity.
On the other hand, imagine you have two choices. You can either lie, or Google Chrome achieves 90% market share, all of web runs on Pepper, and there is no more open web. (Let's call this world "Google Earth".) Mozilla's mission is to prevent such world, right? Do you seriously think not lying is the right thing to do in this case?
Now imagine you have choices of lying and making Google Earth 10% more likely.
Now imagine you have choices of lying and making Google Earth 1% more likely.
How much Google Earth worth is not lying? Eich probably believed him being CEO is worth some reduction in probability of Google Earth. I would be surprised "not lying" has more utility than such probability reduction. I conclude he didn't decide not to lie because of utilitarian calculation.
It's ironic that bigots of Brendan's ilk strongly believe that it's possible for gays to change their sexual preference, while they continue to cling to what they believe in the face of all the facts that prove them wrong.
The collateral damage of advocating a world with more liars (which is what you are doing) is gigantic, because you are now forcing everybody to waste (more) mental energy on trying to discern truth from lie.