Because he sounds way too polite. Really afraid to step on any toes, no matter how slightly.
EDIT
Of course, this comes from me playing games like The Tyrant, Parental Love, Harem Hotel and Waifu Academy.
You're probably right in and of itself, or by comparison to those games.
Thing is, in Chapter 1, they gave us (a few times) the option to be alpha male, and it led to the GAME OVER screen due to a choice or a lack of points when D basically said "Fuck you. I'm out of here".
Now, instead of (IMO) wasting resources, they assume the MC "learned" and is treating others with extra politeness.
You hate it, you hate it... no problem. But DMD from the start wasn't a "I'll fuck your daughter, your mom, your sister, your wife over your dead body... and when the cops try to arrest me... I'll kill them and fuck THEIR wives over THEIR dead bodies."
That's a totally legit kind of game (like Tyrant and others, as you said) but it isn't DMD. Personally, I find that there's a LOT of Tyrant like games out there, and very few DMD type games... but that's just me.