More like why can't chinese authors not write dog shit stories and actually keep true to real logical ways a person might act. Instead, shit authors ruin their won characters by having them change 180 just for the sake of a god awful pairing cause they are the "two main leaders of the story". Just... stop it, write better. If you wanted to have them end up together, then don't have one side do something so horribly to the other that would NEVER be forgiven.