Yeah well, that's if we ignore the fact that Nodoka recived a time-space bullet during chaos arc in order to save Negi, but seems that doesn't count to you. Nodoka plays the role of the introverted character, insecure of what to do and looking for answers in his oun thoughs with her artifact, so it's hard for her to even talk to Negi, whom she is in love with. Asuna, on the other hand speaks her mind even when she shouldn't, so it looks like she cares for Negi more just because she talks a lot more. About Yue, don't forget that even she admits that what she said during the festival was, in part, her selfish ideas.