He is right in that the start is some of the worst writing I've seen in any game I've tested here. It does get better, but I nearly dropped the game after first 5-10 minutes because of how badly it was written.
In Ema's case that's kind of the point. The MC does more or less hate her, too. She's the "arrogant girl that turns out to be massive masochist/humiliation fetishist" archtype so MC putting her down at every turn is both the kink she represents in the story and the best way to get her going despite what she keeps telling herself and the MC.
I dont' think the trope is that common in most western media, but I know in eastern media "arrogant rich person that gets slapped around by MC" is likely the most overdone trope there is (especially in trashier genres I personally enjoy like cultivation stuff), to the point where there are entire series that just essentially repeat the cycle of "MC meets yet another arrogant rich person, arrogant rich person insults MC, MC slaps around the arrogant rich person and angers their family, MC slaps around the entire family of the arrogant rich person".