Ann: 2020 AGM Presentation, page-56

Not sure if you're serious there...

Shorters often do the best, most insightful research in the market. Usually independent and contrarian. There's some classic examples. Slater & Gordon, Vocation, Blue Sky etc...they uncovered material information that the gullible long side completely overlooked and then even ignored it post publication.
Yes they'll be wrong at times too.
Some shorters are momentum based, valuation based, some are naked short, some are disciplined pairs traders.
They are doing the same thing as the long side, just take the opposite view.

p.s. I hope they are wrong on TGR. I just don't like short interest spikes like we've seen, it alerts me to think there may be an genuine insight behind it.