Wow. Tough question!! I'm not sure.
To be truly profitable in the long term, I think greed must be relegated to the backseat. And in the short term, I think greed and profit are really two different "objectives".
I have seen first hand, greedy executives (and banks) focus so much on EBITDA that they totally lose sight of the business' overall performance metrics.
Even EBITDAR on occasion. The "R" being restructuring costs during a Chapter-11 re-org.
I think I have to disagree with the concept that competition moderates greed. It may enhance it however, through the desire to keep all others out of a "good thing". IF the playing field were level, I would probably re-think this. But it is not level. Not at all.