Credible arguments can be made however that short-selling itself, especially naked short selling, is an unethical thing to do as the pure possibility of short-selling makes some forms of crime possible in the first place, such as a criminal shooting up the road bus of a German soccer team to profit from falling stock prices [1]. Especially in the era of anything being credibly fake-able with widely available AI tools, short-selling can look to criminals as a very profitable way to make money.
Also, short-selling incentivizes large stock holders to be lazy and not do their jobs. Imagine a huge ass pension fund - they can (and do) make money as the counterparty in short-selling deals. Some see this as a necessary part of stocktrading life (because it provides liquidity), but personally I think that it removes incentives for the pension fund managers to do their job and audit the stock they hold for their shareholders in turn themselves.
Besides: enforcing securities code and auditing companies should not be the job of vigilantes. I applaud the efforts of ethical short sellers, but in an ideal world, that job would be done by the authorities.
[1] https://de.wikipedia.org/wiki/Anschlag_auf_den_Mannschaftsbu...