Energy Future Holdings pretty much demonstrates what might be wrong with private equity.

All players, namely Goldman Sachs, KKR and TPG pretty much recouped their investments in the company so at least they broke even. The suckers might be the folks losing jobs for these companies to come out of bankruptcy.

Also a lot of times PE firms start buying the debt when the company is doomed to fail and trading at a discount to actual value and they have another go at the company post bankruptcy restructuring.