Although Eriri carried the identity of a doujin big shot, at heart she was just a spoiled, tsundere Little Golden Retriever whose brain was not particularly sharp...
Perhaps Sayuri Sawamura had protected her too well, turning the Little Golden Retriever into the least aristocratic child of a distinguished family. As a result, her likes and dislikes toward people were remarkably simple, so it was hardly strange that she would misunderstand Yukino...
It was not as if there had never been hardworking people around the second young lady. She simply had her own rigorously logical way of interpreting what she saw. To use a nearby example, Hayato Hayama had shown his hardworking side before, but had she ever paid attention to it? In the second young lady's view, Hayato Hayama was probably just a nice guy who worked hard yet refused to offend anyone...
She had even agreed with the nickname Sogo had given Hayama—Mr. Little Sun. Yet it was precisely because she had acknowledged his talent for naming things that the second young lady gnashed her teeth whenever she heard names like Hirano Yukinoshita or Plain-and-Ordinary Yukinoshita!
Ahem, ahem...
Setting that aside.
What Yukino Yukinoshita admired was simply "correctness." Working hard was a correct thing to do, so she admired hard work. But hard work could not conceal other flaws. Take Hayato Hayama's nice-guy personality that refused to offend anyone—perhaps some people liked it, but the second young lady was definitely not one of them!
Take Sogo, for example—although the second young lady had been moved by some of his considerate and correct actions, she absolutely could not appreciate his unreliable ways, his thick skin, and, most importantly, his attitude of constantly trading barbs with her every day!
If not for his thick enough skin, if not for the cat