
Based on the assumption that the current Emperor's parent(s) had the same mindset as he does now.
I distinctively remember a chapter, where the MCs visited a part of the empire, where it was basically a slum, leaving the FL astonished to see its conditions (I don't doubt that the Emperor is just as oblivious as the FL in this instance, since he probably got the same level of education as her). Also, I think the story stated on a few occasions that the FL and probably the Emperor, have been living in their own secluded, protected bubble, with their "demi god duties". Even though the outskirts of the Empire is a hot mess/not at all like what's taught in said education. Either way, whether he knew or not, still looks bad for the leader (He'd then be either oblivious or unbothered).
Also, what if, hypothetically, the FL had no obstacles between her and the throne (this means no insight from the ML too). She would've been extremely oblivious and naive. There was always the potential for her to be the future Empress, yet her knowledge is so bias and secluded (which I assume is known by the current Emperor, that is if he knows any better than past her). This also shows that the Red King just wants her daughter to be Empress, because it's her daughter, even if she's inadequate (we already knew this anyways (⌒▽⌒)).
Finally, imo, his enforced stoicism as a "demi god" really restricts him from displaying empathy. Empathy, which is necessary for an adequate leader of an entire Empire.
To conclude, his demi god "traits" are the main reasons why he's a poor leader and an even worse parent :)
Both the current Emperor and the Red King are trash. They are both terrible leaders and parents.