I like him because of the novel. We're not actually able to see his thoughts here in the Manhwa but he is actually kinder than other MLs I've seen and read about. He is used to being at war and being with men that I don't think he's able to adjust yet to treating Maxi a lot gentler.
This is one of those novel that circulates around misunderstandings. So far, Riftan here hasn't seen even the tip of the iceberg of what Maxi actually went through and still believes she's been spoiled rotten. So yeah, i still like him but I can't really blame you and I totally respect your opinion.
And you're actually right about him just assuming things and that makes him a fool but Maxi is also one reason why he still believes this because she is still too scared to come out of her shell and tell him the truth. Not saying anything is just like admitting so I can't really give him all the blame for this one.
Hopefully Maxi tells him the truth sooner though, only then will we see those sorry excuse of a family she has suffer.

This is an unpopular opinion, but I extremely dislike Riftan and think that he doesn't suit Maxi.
Even white haired guy, whose name I forgot, treats Maxi better, teaches her things and helps her improve. On the other hand everything Riftan has done so far is just shouting at Maxi, assuming things about her (based on his own damn expectations) and fucking her=_=
Why y'all like him so much? I get he's hot but he's a toxic jerk