Musk was initially written off initially as crazy for every one of his successful business ventures.
And it's his money to spend as he sees fit.
As for "every one" of his successful business ventures being called crazy, the first one was a dot-com online map of businesses in a given city. Did people say that was crazy? His next venture ended up getting acquired by Paypal, was that considered a crazy business? He invested in/took over Tesla -- I don't know if it was considered crazy or not at the time. SpaceX obviously is a great success. The brain control company -- we'll see. Grok -- nobody called that a crazy idea. Some of his other ventures, like hyperloop and the boring company, do seem more crazy but those escape your claim because they are in fact not successful. His solar roof company wasn't crazy, but it also isn't a success.
In short, Musk has no doubt had great successes, but there is no need to alter history to claim that at every turn he broke new ground when everyone else said it was crazy or impossible.
Nobody did it before.
> acquired by Paypal, was that considered a crazy business?
Before he proved it was profitable. BTW, every business venture I started was considered crazy by my peers.
> Grok
Musk was an early investor in AI.
The Boring Company is successful. It has found a profitable market boring holes for infrastructure cables and pipes.
People said him buying Twitter was crazy. Oops! (What annoyed me about that was I had some Twitter stock, and it was forcibly sold to Musk. I wanted X stock instead! Alas, it is private.)
I put my money where my mouth is. I've invested in TSLA and am a happy shareholder.
Such as an internet phone. Like a personal computer. Like a Xerox copier. Like jet engines. Like a pencil with an eraser on the other end. Like interchangeable parts. Like the circular saw. Like electric power utilities.
What he's doing is freakin' awesome, and I wish for him (and humanity) to achieve it!
Look up Robert M. Salter at RAND:
"The Very High Speed Transit System" (August, 1972)
"Trans-Planetary Subway Systems -- A Burgeoning Capability" (February, 1978)
<http://www.rand.org/pubs/papers/P4874.html> PDF: <http://www.rand.org/content/dam/rand/pubs/papers/2008/P4874....>
<http://www.rand.org/pubs/papers/P6092.html> PDF: <http://www.rand.org/content/dam/rand/pubs/papers/2009/P6092....>
Similar / more: <http://en.academic.ru/dic.nsf/enwiki/6107059>
Going to Mars isn't a new concept, either. There are probably a thousand scifi stories about such.
But Musk is the first to take action.
If it was so easy designing and launching rockets for 10% of the cost, why didn't anyone else do it? Why did nobody else make reusable rockets? Rockets that could land on the launch pad? The rapid turnaround and cadence of launches?
Musk did what NASA was unable to do.
BTW, the Saturn V rocket engines were scaled up V2 engines. The essential bits were from the V2 engine - cryo fuels, turbo pumps, nozzles cooled by the fuel, boundary layer cooling, baffles to make the engine stable.
The Saturn V engines were lovingly built by hand. Musk's engines are mass produced.
But acting on it at this point is tragic premature optimization. Musk isn't a stupid person so I have to think in his heart he knows his story is more about PR and being seen as a visionary as something that will actually be done in the next thousand or ten thousand years. Even if there is some climate catastrophe that causes 99% of the population to die out and any civilization to collapse, the remaining 1% are better off on Earth than trying to spend their limited manpower to get to Mars, even if some crazy trillionaire has established a beachhead there.
As an analogy, it feels like some person living paycheck to paycheck and having only $20 to spare at the end of each pay period and saving up that money ... not to invest it in some way that improves their lot, but to hire a tax attorney to help them plan how to shelter $1B in income in case they win the lottery.