Another one is "don't lend to insolvent people".

The whole point of a "free market" is a system where there is multiple redundancy so if one thing goes there are many others to pick up the slack and systems are corrected early. neither of these have happened.

So, a more appropriate adage is: owe the bank £1000, you're in trouble. Owe the bank £10,000,000 the bank is in trouble.

The system has no redundancy and debt has been given to those who have no realistic way of repaying it for too long. But for "natural selection" to take its course would bring down the system all together.