Elon Musk's immaturity may affect the perceived legitimacy of his own company, but his actions don't affect the perceived legitimacy of an entire category of the economy like such a jetpack exploit would.
It seems extremely likely that the market cap of Tesla is larger than the market cap of all jetpack companies combined. In any case you assume that any such CEO is concerned with the fate of other companies in the same space, an assumption for which the proof is extremely lacking.