Responses
I know what you mean, sadly I think it's because this is the Japanese ideal, their general society often endorses these outdated "ideal" kind of women there's even a famous nickname for these kind of stereotypes "Yamato Nadeshiko" if you look it up and trace it's history it's pretty disturbing. As cute as it is in a story, in reality women have more character than this and deserve a lot more.
So many of their female leads are so self deprecating. Let me be generous then by also pointing out maybe her love language is words of affirmation and he never said enough? Though he did say (more than once I believe) that he was glad he was engaged to her.
Other than that, I thought it was a sweet story.