She never did. As ive stated elsewhere Hinata as a character is Completely irrelevant to the story. there is no scene where she is involved that she could not be removed and replaced to the same or greater emotional effect by another character with better development.
the character is quite frankly largely redundant, and one dimensional.
Exactly.
You could easily remove Hinata and replace her with someone else while slightly shifting some words around and, in terms of the main story, it would cause no real difference.
It's why when people try to bring up Hinata's confession, for example, and try to say that Naruto reacted the way he did because he "realized that he loved her", I have to remind them of the type of guy Naruto was back then and that he would have reacted that way no matter who was in Hinata's general position (with or without any confessions). It could range from Sakura all the way down to some random nameless villager, but Naruto would have exploded in a rage either way because he viewed everyone in Konoha as "precious" to him, so to see any of them "die" for his sake right in front of him would result in him raging out of feelings of guilt and failure for not saving them.
What began in the late 90's? As for the movement towards moe. Two possible reason for it. One it a reaction to too much tsudere. When there is too much of something there is a reaction, which means that it will eventually bounce back to tsudere. Or. Two it because the otaku have currently taken over the anime industry and they love moe. Remember moe are the shy girls that are in love with the main character that react to everything bashfully and submissively. There easy to get and easy to keep and maintain. Which is part of their appeal. Tsudere guys have to work to get the soft center which is a pain for otaku who probably never talked to a woman for any long period of time that they didn't have to buy time for or are related to.
Such people want their girls ready-made for them rather than actually have to develop any meaningful relationship/understanding with them, with possibilities of low points. This only goes back to the general belief that such people don't actually want an equal partner for a relationship but simply a slave for their sexual whims.