Actually, I am in fact a fan on Nanoha herself, as she's one of the rare heroines who's self-confident in her own abilities and doesn't let her own insecurities mire her determination to do what needs to be done, a trait that only go stronger as she grew up. It also helps that she's the poster girl for MAXIMUM FIREPOWER.
However, objectively speaking Nanoha isn't really of supreme importance character wise to her own franchise. It's similar to how in most Macross shows after the original, while the show is named "Macross", most of the focus is actually on the Valkyries, and the eponymous transforming battleship is at most a side dish.
Just because I'm indifferent to Nanoha not appearing in a series set in the franchise named after her doesn't mean I don't like her.