Because designing systems that work well is difficult. It takes years of experience to develop the muscle memory behind quality systems architecture. Writing the code is an implementation detail (albeit a large one).
Because coding bootcamps and CS programs were churning out squillions of people who could type the code but had poor design and analytical skills, because there was a time where being able to implement Dijkstra on a whiteboard would get you 400k at a FAANG.
Bootcamp grads are basically obsolete now. The real skill has always been the ability to make good design decisions and that's still the case in the LLM era.
I beg to differ. I know for a fact that some companies started hiring people with LLM experience, whose only expertise is spending all Copilot enterprise account tokens on their first week at the job and proceed to whine that the lack of tokens was stifling their creativity.
Say what you may about boot camps, but at least the people getting hired could do things and understand what they are doing.