Interesting problem, but it's hard to find an answer beyond personal opinions and sensitivities. Why did PF pull into a stall? Even the Human Factor Group at BEA didn't find a convincing answer. He maybe thought of an overspeed situation. But how did he come to this conclusion? And why didn't PM stop this catastrophe?
Were they incompetent? They passed all tests, and there were no incidents that we know of. Where they competent? Well, at least the lack of situational awareness and bad CRM doesn't show Air France as a breeding ground for good practices.
I think (speculate) that Bonin had an acute attack of fear of falling down, i.e. panic (the professional term "startle factor" is just an euphemism). That's something pilots (I'm not one) probably don't talk about very much, because people who like to fly don't suffer in any meaningful way from it, it's trained away, and experience does the rest. But I'm asking if somewhere in the old "reptilian" brain regions something is still screaming (but not heard): "That's dangerous now, leaving the ground!".
I also wonder if it's a factor that Bonin previously was on vacation with his wife (fiancee?) on board. BEA noticed his nervousness in the 2 hours preceding the event. So maybe his mental state wasn't completely in "pilot mode", and the professional barriers broke down more easily.