Goyoolee:
I honestly don’t know why the writers made their kid such a loser.
Since this drama is a remake of true historical drama, the son character was based on a real character, too. I watched a little of Xiaozhuang Mishi. The son was a brat too in that drama.
I think it is not a lazy writer. This kind of bratty attitude actually very much resounding with real life. Lots of children with parent that coddle them too much, shied away from disciplining them in the name of "they are still a child, just let them be". Do you know how those children behave when they finally grow up and "finally in time to be disciplined"?! Exactly like the little emperor in this drama. Once you pass certain period in child live, trying to instill them with good behavior and discipline is harder than anything.
The little emperor grows up without any father figure. And since he is an emperor since baby, no one dare to say no to him. Add a spoiling from the whole harem to the equation, you get a walking disaster.
Even in the time of his father, Cheng Xu hold considerable power in court. Of course everyone will look up to him when the emperor is still naive child. No one want to listen a child rambling when they try to govern a country. But being a child he is, the emperor cannot understand. So when this little emperor see that everyone else listening to Cheng Xu more than him, he riots.
I blame Ming Yu the most for this. She should disciplined her son from the very beginning so he can grow up to be a good man. Now, we get a good for nothing for emperor. It is her karma for agreeing with Cheng Rui that his stealing the throne is OKAY.