The major problem that I see with the series is the fact of world building and bad use of characters.
World building:
The guy fucking joke with the readers. Than he show us a freaking map divided by countries and ninja villages, but then do practically nothing with it! Fucking Lord of the rings was only one adventure and it showed over 9000 more stuff than fucking Naruto.
He shows level of Ninjas: Genin, Chunin, Junin and hokage, but then do practically nothing with it! He shows level of Client missions: S, A, B, C, D, and then do practically nothing with it! He shows specialized groups of Ninjas: Medical, Anbu, and than do practically nothing with it!(I not talking about Sakura curing, I'm talking of exploring more those specialized groups, for example showing Sakura in a mission given to the medical ninjas).
Bad use of Characters:
So we have four categories of Ninjas: Genin, Chunin, Junin and Hokage. We know that each year, a new group of Genin appears. We know that two times a year, a new group of Chunin appears. To add to the mix we have Specialized group of Ninjas, Medical ninjas, Anbu and Anbu Root. All that but Kishimoto doesn't add practically nobody into the secondary or even main characters? Well, only Yamato, Sai, Danzo and and 3 or 2 guys with Danzo. To make things even worse he doesn't even give proper characterization and screen time to the already known staff.
He promised so many stuff but didn't developed any of them. Looking at the Naruto world and it seems it has nothing but a triangle of interest: Naruto after Sasuke, Sasuke after Akatsuki, Akatsuki after Naruto. That was basically everything that was shown in part 2, but don't get me wrong part 1 isn't that good either, and at least half of part 2 I really enjoyed. Part 1 goes from one ninja mission, to a Chunnin exam, to a hokage hunt, to a Ninja retrieval. While each part, looked individually was pretty great(just like most or at least half of part 2) together they make little to no sense and don't show any world building nor good use of characters.
Part 1:
Zabuza mission -Passing to the next stage to fast -> Chunnin Exam -Taking the Kyubi out of the village when protecting it is the priority is super stupid-> Hokage Hunt -Sasuke betrayal was stupid, sending kids to retrieve him more stupid-> Ninja(Sasuke) retrieval-The promise that Naruto wasn't able to accomplish, for some reason keeps up. Jiraya gives a super good advice to Naruto, to forget about retrieving Sasuke, but Naruto keeps the idea by saying one of the stupider things ever "If that's what it means to be wise … I'd be happier living as a fool..."-> End Part 1.