Question : Why didn’t the financial auditors of the failed Investment Firms and Banks get sued and shut down?
They are paid to represent stockholders and had a responsibility to publish a statement with the annual report if they find any irregularities.
The either lied or are incompetent. Either way, they took tens of millions and did nothing but allow fraud on the stockholders.

Why would anyone ever believe their certification of a companies financial statements again?
financial investment firms

Best answer:

Answer by Shovel Ready
You’ll notice that the SEC got no admission of guilt for any fraud by Goldman Sachs in its recent settlement. The case for fraud was very weak, weak enough so that GS was willing to take its chances in court if the SEC had pressed for this admission.