Omg yes! This has always annoyed me. Like why are they always so dead set on "sticking to the novel" and saying "they ruined the book." Like y r u there in the first place? Why were u even put in their body? Ur a different person. It's common sense it'll be different. If it was "supposed to be like the original novel" y didn't the original person just stay in their body? It makes no sense to me.
Right!
I also noticed that they want the stroy to stay the exact same while taking opportunities away from essential characters. Or they majorly impact a character's life (e.g., by become a spouse, a savior, or a business partner) but expect the story to get back on track after they leave. You being born as the character already changed the story. Unless you become an exact replica of the character you were reborn as, there is no way of ensuring everything remains the same. Even leaving the country might change things.
I never understood why characters would get so obsessed with keeping the story the same when they already interfered and changed the story. Whether you do leave or stay, there will be a butterfly affect. Also, the characters are no longer a book. You can't force your idea of a happy ending on them. They have their own thoughts, opinions, and goals and have the right to change them even if it doesn't align with the original story you read. I like the story, but them wanting to keep an original "happy ending" where he never falls in love kinda irritated me. A story where only the princess is happy doesn't sound too happy ending to me. If the crown prince so happened to fall in love with another woman, would they be mad at him for ruining the perfect "happy ending"? Even if he didn't fall in love with someone, it wouldn't be because a book said so. Don't dictate someone else life. To them it is not a story. Use the story you know as a draft, not a prophecy. It's not like you can know everything about someone from a book. Sorry for the rant.