Comment by soheil

I think big part of a strategy like this is long term. If you want to short a stock you need to make sure the fraud is discovered by other investors. So you probably need to have a strong marketing department that basically thrashes other companies, this may not be a goal a lot of people aspire to. With a short you're also exposed to lose an infinite amount.

And finally "markets can stay irrational longer than you can stay solvent." -Keynes