Sure, they can "build" it, but can they maintain it? Can they only add more layers of mud? How do you refactor the statement "Add a button to download the output as a PDF"?
That's not a replacement for software engineering.
I thought about this for a while now and I think for the class of problems GP is referring to, no maintenance will actually be needed, the tools will just be discarded re-written again -- at least in one-man projects where no other person than the author is needed to create the tool. Maybe in the future some kind of pseudo-code between real code and natural language will be established. This kind of pseudo-code could be as expressive as code but more concise than natural language. I am not certain if it will ever replace actual software engineers for scopes beyond on-man projects.
That makes sense, but never underestimate how easy it is for a throwaway script or tool to become production-ized and a dependency for other production processes.
We've all seen that obscene production workflow built on a Google Sheet or Jupyter Notebook that now needs to support this or that new feature or integration... Add AI-generated tools to the pile.
What's hard about refactoring it? I sorta get the point you're trying to make, but codegen models generate code, but they also understand and explain code very well in plain language. I believe domain experts are smart enough to solve the problems that crop up and maintain their code with help from AI.