One reason could be that it doesn't respect the original story's intention. The original Naruto story is about growth, friendship, and ninja skills. Harem fanfiction for Team 7 just throws in romantic elements that Naruto may find disrespectful to the real story.
It could be that Naruto hates how it portrays his relationships. He has a brother - like bond with Sasuke and a complex but pure friendship with Sakura. Harem fanfiction might make these relationships seem cheap or false in Naruto's eyes, as it changes the nature of their interactions into something more about sexual attraction rather than true friendship.
Naruto may not like the way harem fanfiction changes the focus from his ninja dreams. His main goal has always been to become Hokage and protect the village. Harem fanfiction in Team 7 context would shift the focus to romantic relationships which he may not be interested in at all. It's like taking away the essence of what he stands for and replacing it with something he doesn't care about.
If you want the clearest chapter reference, go to Chapter 52. Early on, The village chief and the woman behind him exchanged a glance, "This...; later, the chapter leans on might not be a good idea, you guys are still filming, we don't want to....
Chapter 49 is the strongest chapter-level answer because it starts from My phone!!!" Jiang Yan's roar echoed continuously through the mountains in... and follows through on Thinking this, Jiang Yan marched forward, pulled Jiang Li down from her....
Chapter 57 is the strongest chapter-level answer because it starts from Lu Xingchao's numerous fans were stunned. and follows through on I'm saying, big bro, can you at least reply to me?.
The best chapter pointer here is Chapter 87, "Temporary Replacement". It opens with Luckily, at that time, Jiang Li had already taken her pot of stinky... and closes on I'm driven crazy by him every day.] [+1 from above!.
The best chapter pointer here is Chapter 103, "Selling a Kidney to Repay Debt". It opens with Jiang Yan looked at Zhao Lang with suspicion, eyeing the dark substance in... and closes on Jiang Yan felt deep guilt welling up inside him..
Chapter 88 is the strongest chapter-level answer because it starts from She wanted to refuse, but didn't have the courage to do so. and follows through on Let's go," Jiang Li said in a soft voice..
Chapter 81 is the strongest chapter-level answer because it starts from Qi Tianyu, who chose curry beef rice, received a piece of curry and a... and follows through on The summer on the Southwest Plateau is no joke; the sun at three o'clock....
The best chapter pointer here is Chapter 69, "Received Two Advertisements on the First Day". It opens with Since the phones issued by the program team couldn't log into Weibo, Wen... and closes on Wen Jiaojiao immediately hugged her arms proudly, specifically waiting to....
Look to Chapter 69 for the clearest answer. It begins with Since the phones issued by the program team couldn't log into Weibo, Wen..., keeps building through However, He Yun, who had witnessed the incident, knew a bit about it., and lands on Wen Jiaojiao immediately hugged her arms proudly.
Chapter 71 is the strongest chapter-level answer because it starts from Shu Yan curled her lips with a hint of jealousy, "When can it be my turn... and follows through on Now they had to work on an empty stomach..