I'd put it down to the use of debt at consumer AND government level.
Once a borrower cannot repay their debt, the creditors have the debtor by the short and curlies.
Thus the creditors can choose whatever interest rate they like, using the threat that they will take all their money away from you and lend it to some other schmuk! So the Capitalist can capture all wealth creation for themselves without lifting a finger.
Look at how they totally subverted the democratic process in Greece for an example!
There is a way to get out of this problem, but it is for a brave government