I think the key is he didn't know he was doing that. SpaceX and Tesla (at least, as it was founded) were full of people who believe in what their company was doing, and really wanted it to succeed. And if part of what it took to make that happen was helping to create the illusion that their billionaire mascot was a real-life Tony Stark, they were willing to play along. And they did so very well that Elon appears to have completely swallowed his own hype (if he ever realized it was hype to begin with - I'm up in the air on whether he's been brain-eaten by dictator disease, or if he never had any self-awareness to being with). And now he's the naked emperor, absolutely convinced that he's fully clothed while freezing to death.