The return of Keith Gill, the trader commonly known as Roaring Kitty, has sparked a great deal of enthusiasm. All sorts of meme stocks and heavily shorted companies are seeing their share prices rally on this development.Companies aren’t necessarily good investments simply due to high short seller interest, however. In fact, many companies that are heavily shorted have major structural problems. Those include poor balance sheets, unprofitable operations or questionable levels of management competence.Howeve ...