In a blog post from 2009, Twitter Creative Director Doug Bowman explored why he left the Visual Design position at Google. He inclined more towards a whole designer vision of a product instead of just relying on data.
Yes, it’s true that a team at Google couldn’t decide between two blues, so they’re testing 41 shades between each blue to see which one performs better. I had a recent debate over whether a border should be 3, 4 or 5 pixels wide, and was asked to prove my case. I can’t operate in an environment like that. I’ve grown tired of debating such minuscule design decisions. There are more exciting design problems in this world to tackle.