They did dive into this just a bit more in the novel. But, they made it fairly realistic since in old times anyone with a disability was considered less, especially in the royal family because many people see disabilities as a punishment from the above. So it was a huge disgrace. The author wasn't trying to make the emperor into a good dad either. The MC even thought of this, that he's vain, selfish and cares much about his image. But he can be a good dad sometimes, that's how most problematic parents are unfortunately. The MC knows this and she's trying to handle it and navigate the royal families selfishness for her own survival along with the survival and safety of her mother and brother. Even in the end, the author gave the emperor a fitting ending.
They wouldn't be appreciated especially in the imperial family as they need to be seen as spotless. Plus, the level of responsibility and regal dignity necessary for a prince wouldn't be possible for someone with a mental disability.
But yeah the idea of complaining about "ableism" in ancient China is hilarious. The emperor is still a shithead though.
Honestly that pissed me off too but in that era even ugly birthmark was considered shameful and many peasant women would voluntarily or forced to abandoned their children to die so I think it's his luck to be born on imperial family as they had to save face and didn't kill him.... But anyway no matter how many times I read these ancient time novel or manhwa or dramas it's a hard ball
Even today that happens... a lot more lowkey and subtle but still does. And while we are still learning and becoming better in dealing with people with all kinds of disabilities I also think is important that we do not erase the past of how badly they were treated so those mistakes aren't repeated in the future.

Really enjoying the story and its concept! But omg does it peeve me whenever a manhua EVER brings up a character with a mental disability. (I dont think I've ever read one with good representation)
The father literally gets on my nerves trying to act like he suddenly loves his son as if he wasn't just hating on him since birth for being (i assume) autistic.
Solving the premature labor case didn't improve shit either, just proves they blamed the son's "dumbness" on the poison incident.
The conversation between the grandmother and father sounded like "Thank God, now I know my son wasn't meant to be born that way! It only happened because of the poison."
Even if that were the case, it doesnt change the fact they just completely glossed over their inherent ableism. Imagine if the mother wasn't poisoned and he was just naturally born that way? Yeah they can fucking eat shit. I also hate how most of the time some characters only "like" him cause he's the mc's brother...
The mc was practically hauling her ahh to desperately make the father like her brother by "functioning normally," like that shit got me FUCKED UP!! CAUSE HE FELT GUILTY FOR MAKING THE MC TEACH HER BROTHER TO ACT "NORMALLY"?? BUT HAD NO MENTIONS OF GUILT TOWARDS HIS SON HE NEGLECTED HIS WHOLE LIFE!??? LITERALLY NO ONE CONSIDERS HIS FEELINGS, WHAT THE FUCK!!
If the brother just got treated as equally as the other princes, he would have already been able to do everything the mc was trying to desperately teach him (since he wasn't even that high on the spectrum).
It literally makes no sense to me how they just glossed over that shit as if it's nothing, not even a hint of angst or groveling! Like damn, the father couldn't even provide a simple apology!??
It rubbed me the wrong way when he tried to comfort the mother after arresting the culprits, like i couldn't tell if he was implying he felt bad for the terrible treatment from the other wives or the fact she gave birth to the autistic son??
I freaking wished they dived deeper on that topic cause that "revenge" was fucking garbage. My boy deserves better, being a plot device freaking sucks cause I would have LOVED to see his pov!
I hope they jump the father and kill his ass tho, he ain't worth shit