Stating the obvious, but Elon is not managing two public companies.
SpaceX is a monster success, and a huge enterprise … but it hasn’t IPO’d, and may not for a long time. Musk is only the CEO of one public company. And he’s only chairman of SolarCity asnotes. That’s work, but nothing like being a CEO.
The difference may be a lot of form over substance, but your responsibility to a small group of ‘sophisticated’ VCs and similar private investors (SpaceX) is quite different from your obligations to 1,000s of shareholders you get after an IPO (Tesla).
Actively being the CEO of two public companies, each in the spotlight, one of which appears to be struggling (perhap only “appears”), the other of which is in one of the most competitive spaces on the planet … is a big deal.
It’s also pretty bad arse if you ask me.