I'm not sure I'm following you. Creating market value and returning money to the investors as an ROI are not the same things. An earnings call is an opportunity to tell shareholders when - and if - they can expect some of their money back by giving them a more complete picture about how the company is doing. It is part of the role of a CEO in a publicly traded company to continue to inspire investor confidence. Value creation is the easy part, value capture the hard part and without that second bit Tesla's stock will implode. So he will have to talk to those investors to address their worries or the stock value will drop rapidly.

A crazy high valuation is no guarantee that a company can not go bust at some point, though in Tesla's case if they run out of money all that will likely happen is that their next round will be one at a lower valuation and with a group of investors that cares less about the short term.

Elon made the decision to play on Wall Street, that decision comes with some responsibilities and it is downright strange to see him literally bite the hand that feeds him. Without the cash he picked up through the IPO Tesla would be in a completely different position. He's made a couple of boneheaded moves (such as rolling Solar City in with Tesla), which have so far been accepted because of the halo and the promises. But there is a limit to how far that will stretch and I'm confused why he would stretch that on purpose if he has other alternatives (such as simply answering the questions). If he doesn't have any answers, which is one way to interpret his refusal, then Tesla is already in trouble.