What objective evidence do we have that Musk is smart?
Basically: he's extremely rich
Working hard and being very good at negotiating compensation packages and picking the right companies/products to be involved with (and a bit of luck) are all sufficient for exorbitant wealth though.
E.g. there are plenty of people just as smart as Bezos who didn't hitch their wagon to the "sell something easy on the web" idea at the right time
What is a secular term for prosperity gospel?
Social darwinism.
I doubt it. He was born into money and was lucky enough to make some excellent purchasing decisions. His various talks and arguments on the internet show him to be fairly stupid in my opinion. I've heard tell that his successful businesses are mainly successful when the staff learn how to manage Musk and prevent his dumbest ideas.