When you stop regulating, you get short-run benefits (regulatory cost avoidance)) and long run damage (catastrophe expenses).
That's what we discovered with BP. Folks cut corners because the profit motive makes it seem sensible to do so.
Republicans are simply thick and lacking in normal levels of human concern. Or they enjoy their catastrophe cycles centred on their ignorance and sociopathy.
The market long since decided. It decided it doesn't care if employees die on unregulated oil rigs if the money equation makes sense. It's only human beings intervening to force different incentives/disincentives that change the way markets operate.