Well, he hated working for a company where engineers were second-class citizens, and all the staff were treated as fighting cocks.

I'd imagine that at Facebook, engineers are treated as first class citizens. I dislike Facebook as a product, and I'm not sure I trust Zuckerberg, but I really respect the company. Roughly 200 engineers running a tech product that millions of grandmas use is no mean feat. I bet they don't treat their engineers as mere cogs in a machine.