It is _hard_ to start a successful car company, let alone one on an untested platform. He did it, and it taught China how to build the future of cars.
It is _impossible_ to build a successful rocket company from nothing. He did it, and SpaceX is now ~60% of _worldwide_ launches.
He's had plenty of failures, but Musk is what people are buying. He's gross and annoying, but I wouldn't count him out, and I'm rooting for his success.