No wonder it's so difficult for the Emperor to accept advice. The people around him praise him daily as wise and unbeatable, peerlessly sage. Even if he doesn't initially think so, with time, he'll come to accept: I cannot be wrong.
The ones in error are the ministers, who fail to comprehend his far-sighted vision.
The world's troubles are caused by these mediocre ministers!
Moreover, the Emperor, in order to maintain his authority, is unwilling to admit mistakes.
Back when Emperor Han Wu issued the decree at Luntai, it wasn't an apology, but a summary of gains and losses, and a realignment of the country's development direction. It's just the later generations distorted it to force imperial concessions, calling it a decree of self-blame.
Clever emperors grasp this fact clearly.
So unless it's absolutely necessary, even the most feeble emperor wouldn't issue a decree of self-blame, thinking there's a mistake on their part.
