Well, there could be several reasons. For one, some fans might not have liked Sakura's character in the original Naruto series. Maybe they thought she was too whiny or that her actions towards Naruto were unfair. So, they write these fanfictions to create a world where Hinata gets more attention from Naruto and Sakura is sort of pushed aside. Also, fans might just be more interested in exploring the Naruto - Hinata relationship further and bashing Sakura is a way to do that, highlighting Hinata's positive qualities in comparison.
Some fans might write it because they're big fans of the Naruto - Hinata pairing. They feel that in the original story, Sakura got in the way of their relationship development, so they write fanfics to change that. They want to see more of Naruto and Hinata's love story without Sakura's interference.
There are a few motives. One is that fans who love the Naruto x Hinata dynamic may feel that Sakura's character was overrated in the original. They believe that by bashing her in fanfiction, they can give more focus to Naruto and Hinata. Another reason could be that some fans have their own ideas about how the story should have gone in terms of relationships. They might see Hinata as a more suitable partner for Naruto and use the fanfiction to rewrite the narrative, putting Sakura in a less favorable light to make their preferred pairing stand out more.
If you want the clearest chapter reference, go to Chapter 146. Early on, Director Sun: "???" Jiang Li smiled and said, "In the past, the show crew...; later, the chapter leans on But most of the dishes tonight are made by the villagers..
Chapter 153 is the strongest chapter-level answer because it starts from Wisps of smoke gradually rose from the small kitchen. and follows through on After leaning in, he saw Jiang Li and Zhao Lang inside the kitchen..
A practical answer is Chapter 175, because it turns the idea into a concrete scene. The chapter opens with Wen Jiaojiao's eyes nearly rolled back into her head., adds pressure through He couldn't say anything;
The best chapter pointer here is Chapter 120, "Jiang Li Can Actually Do Acupuncture?!". It opens with Facing the sudden and somewhat strange request from Jiang Li, Director Sun... and closes on Drink this." Wen Jiaojiao looked at the half cup of thick substance:....
Chapter 119 is the strongest chapter-level answer because it starts from What is Princess Wen talking about? and follows through on For some reason, he always felt there was a mysteriously calming power....
The best chapter pointer here is Chapter 142, "From Enemy to Best Friend?!". It opens with The ingredients for making Buddha Jumps Over the Wall were still on their... and closes on Wen Jiaojiao immediately lit up and stepped forward to hug Jiang Li's arm..
Chapter 171 is the strongest chapter-level answer because it starts from The afternoon rain stopped and started again, making the air even more... and follows through on They weren't any big shots; did they deserve her to personally run over to....
A practical answer is Chapter 157, because it turns the idea into a concrete scene. The chapter opens with It was already the last day of Flash Change in his dream., adds pressure through So he was being coerced into compliance?, and ends on I'm laughing myself crazy, do actors all have such.
If you want the clearest chapter reference, go to Chapter 166. Early on, Only after everyone in the small courtyard had left, did Zhao Lang stride...; later, the chapter leans on Through the window, he saw the girl sitting at the table reading, her face....
If you want the clearest chapter reference, go to Chapter 136. Early on, A few people retraced their steps back to the place they had just been.; later, the chapter leans on They continued straight up the mountain path until the trees became denser....