I feel it is an issue for Musk (and to some extant for Trump). They have built up their “brand” based on their personal reputation. Musk isn’t just selling cars or internet access or spaceships; he’s selling the idea that he’s a financial genius and people should buy shares in the companies he runs. So screwing up the economy and being revealed as a financial idiot is going to hurt his ability to sell products.
The same is true for Trump but in his case it’s more of a past issue. Trump was never a financial genius but his days of needing to pretend to be one are over. Now he’s making money by pretending to understand politics.