I had no idea that that Diego worked on Inktomi. Although it makes sense why IndexTank worked fantastically. If I had to pick one reason why Google triumphed (and you can only pick one), I think it would be their Page Rank algorithm. It added that extra bit of awesome-sauce to and already tasty stew.
The Inktomi managers had the point of view of a generic MBA.
Everything followed from that difference of view.