Like in many high-skills high-competition jobs, people are selected on how much they can endure, not just how good they are. I've seen many excellent people just quit because the pressure with useless tasks was wearing them down. I often heard them tell me "I don't want to become a zombie like all of them" or things such as "Look at them, they are all trying to reproduce what they have been through because they have been convinced thats how you select good people"