I've actually theorized that the ending and what was set up for Boruto was out of spite.
Here's how it works. Naruto ended up consuming Kishi's life. SP, SJ and all the rest kept pushing him to expand the story, far further than he originally intended to. Kishi wasn't able to spend time with his wife and kids like he wanted to, instead having to focus on a story he was losing passion for and an incredibly demanding schedule. What's worse, the suits made it clear that they wanted to keep the franchise going with a next generation angle which meant that Naruto couldn't fix the ninja system (I've made similar claims about Tomino and the endings of Zeta/ZZ Gundam being driven by the fact there was another Gundam installment planned to come afterwards).
Naruto had taken over Kishi's life, so Kishi struck back. Naruto didn't marry the girl he loved, and has a dysfunctional relationship with his son. His son has also received extensive training as a ninja, and whose goal is to serve the future hokage as their shadow ops master when Naruto was against how the ninja system dehumanized it's members. In addition, Boruto acts out like Naruto did but Naruto doesn't care, instead telling Boruto to endure the lonlieness when Naruto's greatest strength came through the bonds he established with others. Naruto is also continuing to keep the truth about the Uchiha a secret in order to serve the village, while Sasuke and Sakura have a sham of a marriage. And when the script for The Last was presented to him, he realized how awful Naruto and Hinata came off as so he gave his approval.
In the end, he set out to assassinate Naruto's character out of spite with the things he established for the sequel. SP, SJ and the rest didn't realize what they were given until it was too late while Kishi himself until recently was retained on Boruto's staff. Guess there is no such thing as a perfect crime.
Sounds likely.
Kishimoto was getting tired of the manga even by the start of the war arc. I think what he was holding onto to keep going was; he was doing it for his family. I think he even said that in some interviews while the war arc was going on. He wanted to continue to write his story well enough to both make his children and parents proud, and he continue to add NS Mk OR scenes to show his wife how devoted he was to her. When he was eventually forced to make the pairing nH instead he originally tried to justify it as that's what the fans want that was supported him for 15 years. Once that clearly wasn't the case. He had upset his wife by putting a price on their love, upset his children by upsetting their mother, and probably disappointing his dead dad who died roughly a year before the ending.
Chapter 700 had negative implications. But. They could have been easily turned around. Naruto could have learned from Bolt's complaining and been a better father, and Sasuke was implied to have visited every once in awhile. He at first tried to deny and justify it, at first. But by the time of the gaiden he was truly angry and lashed out. Then after that he was just resigned, disinterested, maybe spiteful, and just wanted to leave.
The character assassination, if was intentionally taken place was just until they let him leave so he could do anything else. They had put him on Boruto because they fear it would collapse without him, any sabotage he did commit was just to convince them he was more trouble then he was worth keeping on in order to let him leave.
Edited by Bail o' Lies, 29 December 2017 - 09:53 AM.