The thing is for most places the kind of code they write is good enough. You have painted an awfully pessimistic picture that frankly does not mirror reality of many enterprises.

> What does it say when a compiler expert that knows multiple compilers pretty much by heart, with access to thousands of tests, can't even write a C compiler?

It does not know compilers by heart. That's just not true. The point of the experiment was to see how big of a codebase it can handle without human intervention and now we know the limits. The limitation has always been context size.

>By which I don't mean they never do, but you really can't trust them to do it as you can a programmer. Knowing to code, like knowing to fly a plane, doesn't mean sometimes getting the right result. It means always getting the right result (within your capabilities that are usually known in advance in the case of humans).

Getting things right ~90% of the time still saves me a lot of time. In fact I would assume this is how autopilot also works in that it does 90% of a job and the pilot is required to supervise it.