As @Cgwinning reminds, there have also been points where shorts have been momentously successful.
And you can argue that shorts provide an important role in the markets - cutting down overinflated stocks.
Big issue with shorting from investor side (other than unlimited losses) is that in general markets go up more often than down, so you have to be smarter than the general trend.
From a society side, aggressive shorting is sometimes seen as vultures feasting on a corpse. But then without vultures the savannah might be covered with corpses.