Not bias, but rather a prior. If you know someone quit Google, finding out they disliked a lot of things about Google doesn't give you much more information.
I don't know if I disliked a lot of things about Google. Otherwise, I would have left long before my 6.5 years. I turned down requests to join other companies while at Google. I couldn't have disliked that much of it. :-)
And the opposite: we often see many posts by current Googlers describing it with rose-tinted glasses, all unicorns and rainbows. I'm waaaaaaaay more interested in hearing from people that left Google, especially recently. Also more interested in perspectives from folks over 30, and ideally over 40.
