1. Failure to resolve major plot points such as the cycle of hate. Seriously...they answer was the enemy of my enemy. Their differences caused wars. WWII is an obvious instane that that kind of papering over doesn't eliminate the underlying differences. Once the reason they united goes away those differences have a nasty way of returning. People just hate anymore because....something.
2. The complete abandonment of accountability and responsibility.
3. Constantly raising and side stepping moral issues.
4. Letting a mass murderer get his happy ending and live vicariously through Kakashi.
5. The complete ignoring the obvious objectors.
6. Kaguya and Black Zetsu and the complete failure to develop either.
7. Part 2's constant blame shifting from characters to designated a**holes.
8. The Failure to resolve Naruto's feelings.
9. Not seeing Naruto becoming Hokake.
10. Naruto's and Sasuke OCC behavior.
11. Ino behaving like her Part 1 self.
12. Sakura behaving like her Part 1 self.
13. Everything about the 693 reset button.
14. Spending an enormous amount of time building parallels only to turn around and ignore them
15. Constantly reaffirming Naruto's feelings dedicate only to abandon it for no clear reason.
16. Leaving that justification for a movie because of the obvious hole that's left.
17. The constant use of strawmen.
18. The haphazard slapping together of pairings that have no basis in anything, but simply for their own sake.
19. Having Naruto become Hokage will somehow being constantly bailed out of having to make tough decisions or justify anything.
20. Obito is a cool guy.
21. Always reaching for the low hanging fruit...that the other reality of IT was a lie wasn't the worst thing about it. Not even close.
21. Failing to effectively call Obito out as the complete piece of kitten he was.
22. Seriously, Rin had nothing to say about what Obito had done? In her name. What price did he pay for that again?
23. Team Not Seven. Their existence made no sense. Why they stuck around made no sense. And despite their lingering stench they are suddenly AWOL from the ending?
24. Orochimaru being reduced to cheap plot device. No idea why he helped, what he got out of it, and why he was just ignored. Kinda like he was a murderous monster the whole time. Even his resurrection was bullsh**. What was the motivation. There was none.
25. The mass Pain resurrection.
26. Izanami. Cheap plot device and a technique whose existence made no sense other than a pathetic way to "reform" Kabuto by undertstanding his true. Why his true self couldn't be crap? No idea. But apparently that was impossible.
27. Naruto completely wiffing on the fact that Itachi was one, if not the, biggest reason Sasuke went the direction he did.
28. Pretending Itachi didn't murder children when he totally did as a way of trying to blunt the damage it does to the whole idea of good Itachi.
29. Resolving the Kyuubi reveal off screen.