However you have got to remember that this is not just another company, it's not just another brand. They've already changed the world, it's all there in their track record.
My personal theory is that Musk knows this and his real objective is to provoke car manufacturers into competing on electric. From Musk's point of view, the win is likely not Tesla making any significant amount of money for shareholders but instead it driving the whole market towards electric, thereby achieving the "real" objective of lowering emissions.
Many of his behaviors over the years suggest this could be the case: publishing a 'master plan', releasing Tesla's patents, noting the stock price was "too high", and sinking all of his PayPal money into SpaceX, Tesla, and Solar City (and then borrowing to pay his rent).