If the rocket company was in the stock market as its own thing, not as an extremely complicated bundle, it would not be priced anywhere as high as it is now. I would expect that company to be healthy for quite a while too.
The actual difficulty we have with the modern tech company, which is at its worst with Tesla and SpaceX, is that we are really seeing a price or large conglomerates, so they are extremely hard to price. If they were all split into individual companies, how much of the market cap would go to each? I find the bundles to be rather anti-investor.
And no, it's not just those, and not really just tech companies, but that's where the problem is at its worst, as that's where expensive investments some of us consider worthless are tied with business worth something. Take Amazon. You are buying AWS, a logistics company, an ad company, and as part of this, there was always a devices division selling Alexa. I found Alexa to be a real loser from very early, but there was no way for investors to say what they thought the division was worth. The Amazon es execs could at any time decide to invest billions, or invest zero, and given the size of the conglomerate, the price change was going to not be all that high.
SpaceX has many components I would price near zero, where a lot of money is being spent. But as a pile of risky bets, the fact that they are a pile means it's harder to bet against any one, or ten of them. And if it merges with Tesla, that makes it worse. The difficulty in pricing the bundle makes it really easy to hide big mistakes for a while, until they are so big it all crashes. I don't think that is good for investors, or for having accurate pricing, which is one of the goals of a stock market.