Honestly, I can see how Hinata has slipped through the cracks and not become a target in the media.
Let's be real here, there is a certain image imprinted into our cultural mindset of those who watch anime. There's the male fans living in their parent's basement with their love pillow waifu, as well as the female fans who spend their time writing erotic fiction about Boy-kun A passionately making tender love to Boy-Kun B. On top of this, the representation of women has always been subject to criticism especially with the sexualization of underage girls. There's already a definite perception of cringe, and the Naruto fandom has always been a keen contributor to that.
You could say that these issues are more easily hid in Naruto due to it's kid appeal nature in a medium most people have already have written off, especially when there's more prominent anime that are easier to identify as "problematic" like Kill La Kill or Cross Ange. In contrast, Naruto is almost background noise in this discussion. It's prominent, sure, but it's also an anime no one really paid attention to in it's final years until it ended. And what's more, Hinata is not a prominent or heavily advertised character. She's not a member of Team 7, nor is she Akatsuki. Someone would have to get into Naruto in order to discover her, like a rabbit turd in a bowl of raisins. If Hinata was more prominent, I assure you there would have been far more outcry over Kishimoto's writing being seen as sexist.
And when it came to Hinata, she appealed to her fanbase for certain reasons. Why I can't say. They became fans of this character which I always feel leads to a heavy bias, selectively seeing what they want to see and ignoring what they don't. It's also the same principle that allows Naruto's current behaviors to fall outside of most people's attention. Remember, this is a fanbase that other parts of the anime fandom doesn't want much to do with writing the show off as generic shonen crap (aka background noise). The story can ultimately be about unhealthy relationships and broken morals as Kishi pulled turds out of his butt, but a significant part of the fanbase isn't going to care because they're only seeing the good while not thinking it through.
At this point, I feel like I'm discussing a Twilight ripoff. Hell, they would probably start arguing Naruto isn't meant to be a critical darling and is just supposed to be an enjoyable action series. After all, they defend NaruHina's lack of development with Naruto isn't supposed to be about romance while gushing about The Last because it's about NaruHina's romance. And like arguing Twilight, my brain is starting to hurt.