Jobs/environments don't make people rapists. Choosing to rape someone makes you a rapist. Not all thugs are rapists and not all rapists are thugs. They have nothing to do with each other. So don't even try and give him that excuse.
And he hasn't changed. He knows what he did to Euihyun was wrong, pretended to care about him, then raped him to get what he wanted anyway. That's called reverse character development and that's why people who use their brains are annoyed by the author's decision to ruin his supposed redemption arc.
Not that I think a rapist can be redeemable in the first place but they can have good characters development. Even that monster from Painter of the Night managed to pull it off with a sincere apology and actions that support his words until the end of the story.
Read 2 chapters this shit sucks,,, he got raped,, it was disgusting and the ML is cringe as fuck and weird and a rapist he’s not even that hot not that it would make up for the fact he deadass raped the MC