"This makes the whiteboard interview the Best most unbiased process we have to judge other people."

Nonsense. You can just give an SAT style IQ style test loaded with algorithms questions. Far more fair and objective than the biased human interviews we have right now. From my experience on the interviewer side, a lot of good people are rejected due to bad interviewers and the arbitrariness of the process, and many incompetent people are accepted due to the biases of the interviewers. The average Googler isn't as smart as you think. Of course a written IQ test still wouldn't be perfect, but nothing is.