I dont mean to take a position on Musk per se, but I do think there's a reasonable argument that Tesla might actually do better without him. He does bring a certain amount of risk.
I raise this in part because one of the problems with counterfactuals is evaluating a state of affairs that you dont have access to. In fact, evaluation of that alternate state is necessarily biased by the currrent state.
Similarly, if the stock is undervalued, it becomes more costly to raise capital in public markets. So hiring a CEO with poor market perception limits a company's options, even if they're internally very effective.