Perhaps that's not the end of the world. Is Google's primary burden to growth their quality of engineering? I doubt it, so weighing the entire interview on coding skills seems like a mistake, one that is compounded by creating a homogenous culture where everyone has the same blind spots.
The counter to your argument is that many of Google's products, like Google+, feel like something a shut-in would develop. No soul, no emotional appeal, and I suspect it comes out of this engineering is everything (at the expense of product people and creative types) mentality.
What if the "robotic" questions themselves have a bias? They almost certainly do. (They've already turned off people who don't like robotic questions. :P) Demographic diversity is just as important as creative/intellectual diversity - I think diversity of hires requires diversity of questions. It requires some bad interviews, but it creates some great interviews. I've had interviews and been interviewed in both settings; no regrets. White male, though, so hard to say.
So you'd prefer that the interviewers set up situations for unconscious biases to take hold? That would hurt the quality of engineering at Google.