He's writing this to people like you.
As far as I was able to read, not a single mention that Musk has been able to take two or three other previously considered impossible tasks and bring them to completion. Call me a fanboy if you will, but at least my fanboyism is evidence-based.
It's not personal. Musk is not anyone's personal juvenile delinquent (cable TV edit). Why do you care so much whether a single billionaire is validated or not? Why is every time there is an article like this, there's half a dozen Musk fans complaining that someone dare challenge the great Musk?
The fact that we've lost faith in humanity's ability to improve things by taking on large, ambitious projects, even if some, even if most, will fail, saddens me every day. It doesn't prevent me from trying to make the world a better place though, and I hope nobody else was discouraged by low-quality, knee-jerk thinking like this, either.
No, there are simpler questions, like why build inefficient systems like Hyperloops and car sleds when we have tech that works at scale already for the former and we have solutions to the latter that don't require right of way under the most expensive real-estate in the world to build transport systems for transport systems (that Musk just happens to be selling), and will make our urban centers car based for the forseable future when we could be going the other direction?
It's good to praise vision and have heroes but one of the constants of history is that heroes fail (because they're people) and that rate increases as they get further and further outside their original domain. We should be thankful for the visionaries but the way of refining their visions is criticism, not bristling when someone dare do that.
Napoleon ruled the world right up until he didn't.