Indeed, Tesla or Uber have revenues. But their bonds are still lower rated than Argentinian bonds. Can't expect creditors to like you if you're not showing excess cash flow.

Shareholders, on the other side, well. Let's just say that in the 60's or even 80's issuing IPOs was not something a professional investment bank would do. It was considered an undignified exploitation of the naive investor (from "The Intelligent Investor").