But he was hardly a newcomer to Mozilla, having been CTO for years. I believe I read that he had also participated in the drafting of Mozilla's diversity policy.

And as far as him being "allowed" to remain CEO, I was really speaking about public opinion, not about the board's actions, though I am extremely unimpressed with the way the board handled the whole thing. He claimed that he had initially been uninterested in the position, and they talked him into taking it. Given that, they should have supported him a lot more than they did, although they might still in the end have felt their hand was forced.