Everyone's got shorts, but Tesla's short position as percent of float is very high, at almost 29%. GM, for example, is under 2%, and Ford around 3%. That makes it a material point of discussion.
Second, yes, they are probably hedged. But usually they hedge against correlated securities such as industry competitors so they can hedge away risk they don't want to take (i.e., they have a position against Tesla, but no position about car sales in general, so they hedge against the rest of the industry to protect themselves against economic growth raising all car sales). So if Tesla reports good numbers relative to the industry, it will absolutely impact shorts and they are likely to lose substantial amounts of money. What else would they be hedging with? Maybe their bonds, if you had some sort of complicated capital structure arbitrage play, but I haven't seen much of a case being made about the bonds being undervalued relative to equity.
Having said that, I think shorts play an important role in the economy to keep companies honest.