The outcome here shows that executives made the right call. The $5MM fee was easily paid, less than the costs of security, and the insurance company will probably cover it anyway. And the government/people were so outraged that the attackers were met with fucking swift justice.
The company will probably get some grants or something to cover the cost of "securing their infrastructure." Never let a good crisis go to waste.
Any employee choosing to spend millions to avoid the cost of a heretofore unencountered cyberattack would be making a strategic decision, while probably not being empowered to make decisions at that level. So they do not take action.
Bureaucracies do not take visionary action. They stay the course.
Everyone want's to make the calculation and hope it's not them, but if it's everyone at once, or there is no ransom option it's a completely different ball game. This is a situation where we are asking private companies to take responsibility for something outside of a profit motive and the results are some what less than surprising.
Maybe now utilities going to the US for a similar reason will be in everyone's DR/IR plan (even if Colonial didn't reach out to the US admin).
But a more precise calculus would take into account that (1) the proliferation in ransomware is recent and explosive, and (2) getting hit by one ransomware group doesn't mean a second group won't strike soon. (Although I'm guessing the second wouldn't be allowed to use the same ransomware-as-a-service platform, as that would harm the platform's reputation.)