He's trying to make humanity a multiplanetary species while at the same time trying to get humanity off of fossil fuels by completely upending and dominating:
1) The space industry
2) The automotive industry
3) The solar industry
4) Some parts of the world's power grid infrastructure.
He asks a LOT of his employees, and despite his companies being 15 years old at this point, asks for the type of commitment from employees that you would find at an early stage startup.
His competitors are largely government contractors, and government-backed natural monopolies. Because of this, the contrast between working for a company like spacex (innovate or die) is in stark contrast to something like ULA (rest on the momentum you have built over the last 50 years. Go home every day at 5:00. Lobby your boss for 4 day work weeks).
There are a LOT of people who look at the people working at SpaceX, see the insane schedule the work at, and resent them for it.
They are literally trying to save the human species. It turns out that requires some pretty serious dedication, but it also turns out that there are going to be some people who hate you for it when you try.
Also: there have been MASSIVE short positions taken against tesla in the last 5 years. So there has been a lot of negative stories and anecdotes shared about the working conditions of Tesla factors. However it should be noted that those working conditions are approximately the same (or better) than at most other large automobile manufacturers.
