The problem here is that both Elon and investors (as whole financial sector) is currently trapped in the myth of Eternal Growth. They are so trapped in this world where everything must grow, even growth must grow, that they don't see when they cross the barrier of telling themselves fairytales and having ideas that are physically impossible to realize. I'm not sure if this is gullibilty or if they really believe that the growth will never stop or maybe even fear because if they stop doing this, the REAL wold says "I call" and their world will fall apart...

@cstross