> Wonder if it was worth all the time they saved not thoroughly inspecting rail cars.

It was. That's how everything works in the world. You find a reasonable medium between cost and benefit.

Do you get a $5,000 PET scan at your routine annual physical? It would very likely find a lot of problems much earlier than otherwise.

Why doesn't every single road have concrete dividers? Why don't cars have 5 point harnesses and roll cages? That would prevent a lot of accident and deaths.