The self-taught programmer's idea was coded by someone who is no smarter than they are. It will never confuse them, because they understand how it was written. They will develop along with the projects they attempt.
The junior dev who has agents write a program for them may not understand the code well enough to really touch it at all. They will make the wrong suggestions to fix problems caused by inexperienced assumptions, and will make the problems worse.
i.e. it's because they're junior and not qualified to manage anybody yet.
The LLMs are being thought of as something to replace juniors, not to assist them. It makes sense to me.
Repeat that a few hundred times and you'll have some strong intuitions and sensibilities.