> I have no idea why people take outside money. If you can't afford to build it, start smaller, get rich, go bigger
1. To diversify their finances. Going all in means every bet, if it fails, could be your last. (Less applicable for someone with Elon's name recognition.)
2. Some ideas don't scale down. Building a big rocket is a different game from building a small one. The lessons from the latter will apply roughly, at best, to the former. Same with tunnels.
3. To get intellectual and political buy-in. When people invest in something, they take ownership--financially and emotionally. Having shareholders who you can deputies to fight your battles can sometimes beat a hired hand.
I think your second point is the most valid and hard to argue counter argument. I agree, there are things that simply require more capital than people have in their bank. I disagree that diversifying is virtuous unless there is a good reason to. Make the government your customer and your work will always be legal, not so for investors (see: countries "cleaning up" their portfolios, people still use gas though).
1. To diversify their finances. Going all in means every bet, if it fails, could be your last. (Less applicable for someone with Elon's name recognition.)
2. Some ideas don't scale down. Building a big rocket is a different game from building a small one. The lessons from the latter will apply roughly, at best, to the former. Same with tunnels.
3. To get intellectual and political buy-in. When people invest in something, they take ownership--financially and emotionally. Having shareholders who you can deputies to fight your battles can sometimes beat a hired hand.