Simply because it's the first time we've seen the MC take this approach. He usually relies on his silver tongue or catching the girls off guard with his boldness rather than outright blackmailing or raping them. Even on the corruption the MC genuinely cares for the girls and is seemingly trying to be a better person this time around. He goes into business with Gao because he wants to prevent his mother from running into financial difficulties again, he's concerned when Alyvia is upset over Dillan (and not just because he sees it as a chance to get into her pants), he wants to fix things with Viktoria, etc.
The funny thing is, he didn't even need to resort to blackmail. Aden already mentioned how Cathrine is constantly talking about the MC now. He was doing well and likely would have stolen her eventually anyway, as i'm sure we'll see on the seduction path.