This seems unfairly negative. It may strictly be true that his ventures are "still in the early stages with uncertain futures." But the ambition and degree of difficulty of those ventures is also relevant. If you look at Tesla and SpaceX, I'd say the degree of success so far, relative to the degree of difficulty, is quite remarkable.
I don't think it's unfair. How would you view a person in the 1800s who invested a large fortune in electricity or automobiles prior to certain critical technological innovations that made those things practical. He had the right idea and wanted to move mankind forward but he was 50 years too early. Was he foolhardy? Was he arrogant? Was he admirable? I don't know. Mostly though I think he's not worth giving much of a damn about, and definitely not worthy of some kind of cult of personality of devoted fanboys.
I could buy that a few years ago, but EV adoption is taking off and some big automakers are now chasing Tesla's lead. Even if Tesla keels over and fails, their impact will be felt for a long time. Similarly, SpaceX kickstarted a new age in space launches by showing that the old ways really could be improved, getting reusability out from the long shadow of the Space Shuttle, and getting private companies into the game as more than extensions of the government. Like Tesla, they've made a big impact now even if they collapse.
The hero worship should be pretty simple to understand: he's built (with the efforts of thousands of people working for him, of course, it's a huge group effort) amazing things. Every time I get in my car, I marvel at it. He's landed an orbital rocket on a barge in the ocean. Several times! Even if somehow these things somehow fade into absolutely nothing, they're amazing accomplishments.
In addition, I'll bet that if he ended up broke, but having significantly pushed forward various technological ideas, he wouldn't consider it a failure.
Some folks who only focus on wealth would call it foolhardy regardless, though.
