Money?

I mean, they were selling something which didn't exist as a one-off payment for about the last decade, so I'm not sure why selling it on a subscription basis is inherently any weirder. They clearly have the sort of customer base who like paying for non-existent things, so why not?

One of the most notorious liars in history was heavily leveraged and needed the stock to do well, to avoid bankruptcy, so he lied repeatedly for years?

There are a lot of "true believers" in the Tesla customer base so it's an easy way to collect money without doing much. The same mindset applies to the stock: it's not really based on any fundamentals, just vibes and Elon's personality.

When you get paid for not doing anything, you get paid, but you don't have to do anything.

Musk is a con man, he'd accept money for bus tickets to Mars.