Of course they weren't. They were intent on making money - as were the flippers. If that involved defrauding the public they did that. If that involved defrauding a bank they did that. If that involved building a lot of houses they did that. The problem is not the motivation (greed) - the problem is that some actions taken to make money destabilize the economy. An insistence on blaming isolated bad actors, rather than addressing the root causes of the problem, will guarantee that you fail at finding a solution.