The big banks today aren't really banks at all: they're huge proprietary trading houses (that's where 2/3 of their "assets" are).
So the Federal Reserve-- which was created to inject liquidity during a banking crisis-- now serves to inject liquidity (bubbles) into the securities markets.
In addition to being inherently more risky than traditional banking, the higher returns in proprietary trading-- especially for "bank" officers and traders-- encourages yet more risk taking and starves the real banking sector (commercial and consumer lending) of capital.
This is one reason commercial and consumer lending rates are ridiculous multiples of the prime rate: the banks expect to make 15-20% ROI on their "investments," so why should you pay less to borrow the same money? So we have a system that simultaneously multiplies risk and starves the real economy of cash.
The big banks today are financial vampires sucking the life-blood out of the economy and rewarding a corrupt circle of banksters and their political associates.
If the taxpayers are on the hook if a bank fails, then they are in essence a part of the government.