The main point (backed by some historical experience) seems to be that unregulated financial sector takes too much risks and that brings financial crisis. And in such a crisis, common people loose jobs or savings, but banks get saved by governments.
Financial sector constantly tries to get rid of regulations and state control and/or invent various strategies how to exploit holes in legislation, to be able to risk people's money in speculative assets.
Average citizens should be more aware of what their banks are doing with their money and change the bank if they find unethical behavior.