Most of the stuff on which we engineers work ends up in the bin anyway. This is just more spectacular than some manager showing up one day to announce that this XXX M$ project, the one you and many others spent your last 2 years regularly overtiming, is cancelled because mblllmbllbllsometopmanagementfuckedupmbbllmbllblll. I just mention this case because it was the most ridiculous that happened to me but a large majority of others projects I've worked ended up in the bin a way or another, or should have because they are designed from scratch to be useless.

It's the life that they've chosen. It comes with ups and downs.

Can you prove any of this?

Knowing how smart and methodological Musk is, I wouldn't be surprised if the rule at the office is actually to leave your desk and go home at 5pm sharp.

You are prone to make more mistakes when you tired and overworked and I cannot imagine more important place not to make mistakes, than building a rocket.