I think it's more likely they're under no illusion that the moment they fail because what the great and might Musk wants is impossible, or they have to try and explain reality to him they'll be fired, same if they try to explain to him that "yes you could do that, but it would break the law in multiple countries, and no I'm not willing to go to jail for you by putting my name on the paperwork" (Musk's personal lawyer was advising staff they could "self certify" stuff Twitter was under legal obligations to do, those staff had no training or understanding of the legal side of thing because Musk got rid of the in house specialist legal team).
Musk is refusing to honour contracts and firing people for showing him facts, that's not a person you can ever expect to get any "handsome bounty" from as the chances are he's going to fire you for "failing" at an impossible task, or because if he fires you he can avoid that "handsome bounty".
And yes there are jobs that are 9-5, but the longer the hours you work the less productive you become and the more likely to make increasingly obvious but major mistakes you are, because the human brain, like the muscles needs time to rest. There are very good reasons why pilots for example have extremely strict rules on the hours they are allowed to work, and how much rest (and type of rest) they must have before they start a flying day. IIRC pretty much every single study has shown that humans cannot maintain good cognitive function for more than a fairly limited number of hours, and needs a regular "change of pace" in addition to rest to keep working at it's best, and that the effect is cumulative so you might be ok for a few days of "extreme hardcore", but after a week or two you're failing.
It's one of the reasons the likes of Twitter and Facebook, Google etc all had so many "frivolous" things as "bonuses" and "incentives", yes they might have expected staff to work long hours, but they also understood (unlike Musk) how important it was to let the staff unwind, and if you could have them unwind/relax on site it meant they could be more productive (and also the reason they allow things like a day a week for personal projects, those "personal projects" help the people unwind, but also can work out to be more valuable long term than the assigned job, as they may be "personal" but if done on company time the company owns them).
When people say "they can work longer hours and do it faster" I always remember what someone once said (paraphrasing) "it doesn't matter how many women you get pregnant, it still takes around 9 months for the first baby".
