Furthermore, even if that were true there is nothing to stop a malevolent actor, either deliberate, by ignorance, or by lack of better alternatives, to just eat the cost.
Oil and gas, if you ignore global warming, really is very, very cheap.
It's particularly severe when it's up to an MBA running a company, but an engineering education only goes so far in mitigating that tendency: the Koch brothers majored in chemical engineering at MIT. A major component of their education was all about externalities. And yet they've devoted their political activism to nurturing anti-intellectualism in the Republican party specifically so that the GOP would deny any and all externalities.
No one does any risk analysis and the short-term upside makes the long-term downside invisible.
No one knew how problematic pesticides can get. We are just now discovering the effects.