Trend following beta monkeys (TFBM) using Other People's Money (OPM).
They'll never learn.
Because they don't care after they have collected their fees and bonuses.
Herd behaviour does not begin to describe this phenomenon.
The US financial system is designed to maximize financial management returns and encourage the mispricing of risk, and ultimately the distribution of wealth from the many to the few through fraud, fiduciary recklessness, and Ponzi schemes.
The root cause of the US's problems are with the distorted monetary policies of the Federal Reserve, and the regulatory failure of a government corrupted by its financial sector.