I agree that Elon is way too self-indulgent. Forget about the simulation remark, hyperloop is either cynical in nature (meant to divert funds from real trains) or wildly underestimating the costs and safety issues.
However, I think you're wrong about the space junk issue. One of the problems right now is the lack of any way to economically de-orbit legacy space hardware in high orbits. You don't get that without economical access to space.