My guess is that they don’t want him to have the throne.
SPOILER
His mother is a spy so the Emperor raped her and make her the Empress to tied her down and make her his puppet, after the child is born, his mother dressed him as a girl to protect him even the Emperor didn't know, since no one would see a woman as a threat for the throne. that's why even though he was neglected, no one poisoned his meal or sent assassin to his place.
HOLY SHIT WTF
WAIT WTF THE MOTHER WTF :((((((((( WTF EMPEROR WTF WTFFFFFFFFF WHAT THE FUCKK
Yoooo, where did you get this info from, did you find the novel? If so, can you give me the link?
Yo what the actual fuck is going on with the “princess” is that actually the guy who killed her in drag, if so, why is he crossdressing, what’s the point. You know how confusing it is to see “he’s the daughter of”
ITS SO CONFUSING AS HELL