That's exactly it. Too often, management is judged on short term performance. Risks are often ensured, or taken by daughter company that can be dropped. And even when not, they may believe the risk is so small that it's worth taking.
Especially when margins are low, cutting some corners for a small drop in costs can lead to a large increase in profits. And when the damage done to society as a whole, the lives lost, the radiation released, and the animals drowned in your oil, are not on your balance sheet, they don't directly factor into the decision. Only the money they have to pay as a result does, and that's never enough to undo the damage, and often not even enough to scare other companies from cutting similar corners, because letting those companies really pay, would bankrupt it and costs jobs.
That's not how business works. If you wrecklessly drove a company into the ground, you're going to have a hard time finding another leadership position at another company.
That's not how business works. If you can show that you saved the corporation massive amounts of money, and that "the incident" was a one-in-a-million that would _never_ happen to the new corporation, then of course they will hire you for management. See: HP, Yahoo, etc.
He made the company tons of money. I'm sure he would claim it "would never happen" to the new company as well. Yet he's not exactly leading up another energy company, is he?