I guess you can say it's romantic and loving when someone you love is willing to do anything for you, but to harm the people around you with no particularly rational reason, it's way more than a bit extreme.
Even though the ending (, as I have read,) is quite disappointing and confusing, I will forever wonder why the concubine just accepts the actions without blinking. The way the couple treats people is exasperating and it feels like the king doesn't trust the concubine that much. I Honestly want to scream at the characters for all being such buttholes for the lack of awareness of the people around them.
P.S. sorry for my lack of explination