Her name literally meaning "Meat" is an actual plot point though. An adventurer gets pissed at MC for naming her that.
That plot point makes less sense if she's called "Niku"
I guess the word for "Yankee" is the same in japanese as the word for "Delinquent" or "scary" or "gangster". I wish translators would stop using yankee, it makes no sense for any of these.
They built up a game where she was allowed to show several sides of herself to MC. Then he decided to be "a good boyfriend" and only really play with her "normal" personality.
She missed being able to show sides of herself to the MC other than the usual.
In defense of the girl, she only knows the duke through the story where he was a villain. So her standard assumption is "he's evil, and everything he does is a plot"
Its still unfair, but its not *entirely* unreasonable.