It's risk/reward to the people who want to decide how their money is spent, isn't it?

In your example, the worst-case scenario is that someone could die, and that tends to spur on investors to discover the probity within themselves to spend some money avoiding an expensive lawsuit.

But when the devs are complaining about the old code being terrible and making their lives hard, it never seems to hinder them that much to management. They keep banging out new features and fixing bugs, and nothing bad seems to happen. But the drip-drip-drip of bugs keeps increasing, and the new features take a little longer each time, and nobody dies at least, but the thing becomes a haunted moneypit that nobody wants to touch, and you're stuck with it now unless you rewrite it all at huge expense, etc., etc.

Maybe everyone should just treat a piece of software as they would a life. I bet we've all seen some codebases where if it were a friend, you probably would have staged an intervention by now. Your software baby needs absolute care from the get-go until the very end, or it will get sick and probably die, and most likely in a very prolonged and painful way.

The place I used to work in has been hiring (junior) people like crazy. Part of the reason they need so many is the crushing foundational technical debt at the core. When they hired someone to capable of improving that they were unable to merge the changes due to fear, and the management couldn't see the business value of doing so. They've had a few nasty outages recently too. I believe the insides of the Atlassian kit are similarly riddled with technical debt.

An important difference being that in your Ford example, you can just throw new people at the problem while in software it generally needs to be handled in the responsible team.