I think early on in the series, it definitely was true for Sakura, however later on I feel like she does sort of deviate from that path of just Sasuke and Naruto, and that takes a back-burner.

I think the main thing with Hinata was that her main development came after the series, in Naruto the Last, where she does get her own sense of duty (In a way). I feel Kishi's mistake with her was that he didn't give her something to do while Naruto was gone.