It’s not human, of course, and I think this problem actually relates to the fact that LLMs don’t have a world model. They don’t study and think through a design in the way that humans do. They don’t form a mental model of how everything fits together and how that design can be tweaked to most elegantly support a change.
I suspect that this is a fundamental limitation of LLMs, and that design will remain a weak point until some sort of bespoke design AI is bolted onto the side. In the meantime, we’ve got a lot of people producing a lot of code very quickly, and I think the debt in that code is going to be a millstone around our necks for a long time to come.