Nassim is one of the best commentators about what is going on
This video by Nassim Taleb came out a few years. He has been very prescient in exposing how our financial system has become an interconnected fragile mess. We know that he was right if little Greece can cause worldwide financial problems.
His point is that non-diverse, optimized, highly efficient, interconnected systems with little margin of safety are fragile, delicate and unstable. They can make a lot of money until they suffer a disastrous systematic crash. A bit of redundancy, diversity and margins of safety can help keep us safe. We live in a financial system that is loaded with debt and risk, and so interconnected that appropriate firewalls are not in place, and chain reactions and contagion is a constant worry.
Another good point is that frankly all of this is too complicated to fully understand, unlike the foolish experts to think that they have it all figured out.