The day the Ken Lay resigned from Enron starting the events that lead to the bankruptcy, Enron's debt was rated AAA by the S&P. No evidence has been presented that the S&P played any part in the fraud. The subsequent revelations uncovered an accounting shell game that hid the Enron house of cards for years and bilked investors of 11 billion dollars.
Sarbanes Oxley insures the information investors rely on is accurate and verified by the management of the business under penalties of law. Many of the S-Ox cost objections are grossly overstated. It takes more time to dummy up a set of books than to represent the truth. The real objection to Sarbanes Oxley is that it inhibits CEOs and boards of directors from taking stockholders money and running the business like it belongs to them when they are in fact employees of the stockholders.
Sarbanes Oxley only applies to publicly owned companies. If CEOs and boards want corporate jets, million dollar decorated offices and golden parachute retirements, fine. They can do it with their own money and avoid Sarbanes Oxley.