History is full of "emperor wears no clothes" moments.
And anyway, isn't a lot of Musk's net worth kind of theoretical? A lot of it could be, for example, value of TSLA stock, which has tanked since the ridiculous IPO.
Also, if I'm Musk, I'm not necessarily hurt over spinning some of my funds into a company that, while perhaps not worth what I paid for it, still happens to be a real company that now belongs to me, and not just value on a ledger that ebbs and flows with the value of a company I'm no longer directly in control over.
I guess where I stand is that, sure, he could have overpaid for it, but that doesn't mean he's not going to make money from it, or that it was necessarily a bad place to put his money. Time will tell. It does not seem like anyone's giving up twitter anytime soon.