Fragile masculinity combined with wanting to appear sufficiently tech savvy to tech bro investors. Tech bros want nerds because pretty much every dollar they’ve ever made was off the back of some innovation of someone they consider a nerd, so Elon wants to be the biggest nerd to tech bros so they will throw even more money at his dumb projects.

Both of these people could fall off a cliff in a burning Tesla and nothing of value would be lost.