I wouldn't be too quick to judge that it was completely based on greed. It's a little easier to pass judgment away from these conditions. Moral compasses go awry. I say all this having recently witnessed a little such corruption in family estate handling vs. business world. It's decidedly distasteful at close quarters.
Human beings seem capable of rationalizing some very slippery behavior.
Fortunately we have external agencies like the SEC to slap these clowns around. Now if we just had similar enforcement for common sense and decency.