What makes you think that being short on a stock is the same as hoping for failure? I hope Tesla is fantastically successful, but I would consider shorting it if I were doing such things these days. They're two totally separate things.
I don't think they're separate. Shorting a stock means you make money from the stock's decline, and therefore from the company's failure. You hope to make money from your investment, so you hope for the company to fail, at least indirectly.
Furthermore, shorting a stock can harm the firm. Big short positions drive down the stock price, which affects public sentiment (their stock is down, they must be failing, I won't buy their car because they may not be here next year), makes it harder for them to retain employees, makes it harder to raise money by issuing more stock or bonds, etc. By shorting a stock, you are contributing to that company's failure (though of course the effect is miniscule for retail investors like me).
I would not buy even a undervalued stock for a tobacco company, because I don't want to support producers of tobacco products. And I don't want to impede progress in electric cars by shorting their producers, even if I think their stocks are overvalued. There's plenty of other investments available that align my finances with my hopes.
Short selling is nothing more than selling before you buy. If you believe that short selling drives prices down, then you believe that taking long positions drives it up. Neither is true.
Short selling provides more information and better liquidity to the market. It's a good thing.
Of course short selling drives prices down, while long positions drive prices up. That's basic supply and demand. What else could determine prices?
I agree that short selling is overall a good thing, though it can also be abused (e.g. naked shorts). I am not claiming any market abuse in the case of Tesla.
Most people do not buy individual stocks based purely on a risk calculation. They also want to believe that the firms are working for good, not evil, because buying a stock means you own part of that company, and therefore are in some small way responsible for its actions.
Short selling is the same, but in the opposite direction. You own a negative fraction of that company, and so your moral relationship to it has a minus sign. I think that Tesla is a good company. But some people think that owning no TSLA is still too much, and I hope they get burned (financially).
