Perhaps he's simply bored and looking for some entertainment related to his family's history. Fanfictions can be a fun and creative way to revisit the Naruto Shippuden world from a fresh angle.
He could be curious about how other fans perceive the events in Naruto Shippuden. Fanfictions can offer unique interpretations and perspectives that might give him new insights.
One reason could be curiosity. Naruto might be curious to see how fans imagine different scenarios in the Naruto Shippuden universe. Maybe he wants to see how others view his friends and his own adventures.
Perhaps in fanfiction, Boruto is associated with a group or ideology that Naruto opposes. This could cause Naruto to view Boruto unfavorably. Also, if there are false rumors or misinformation spread in the fanfiction world about Boruto, Naruto might believe them and start to hate Boruto until the truth is revealed. And sometimes, it's just a way for the writer to make an interesting and unexpected plot twist.
It could be that the fanfiction simply doesn't meet Boruto's standards for what the Naruto universe should be like. He has grown up in that world and has his own ideas about how things should be. Fanfiction can be very hit - or - miss in terms of quality and faithfulness to the source material. If it's of poor quality or changes things too much, Boruto might hate it.
One reason could be Boruto's recklessness. In fanfiction, Boruto might engage in dangerous stunts or actions that go against Naruto's teachings. For example, if Boruto were to use a forbidden jutsu without fully understanding the consequences, Naruto would be angry as it not only endangers Boruto but also those around him.
It could also be due to a rift in their relationship over Boruto's ninja path. If Boruto decides to take a very different and unorthodox approach to being a ninja that Naruto doesn't approve of, such as using forbidden jutsu without proper understanding, Naruto might disown him in the fanfiction.
Perhaps Boruto disrespects the ninja way that Naruto holds so dear. In fanfiction, Boruto could be shown as being too rebellious, and Naruto, as a firm believer in the ninja values, would snap at him to correct his behavior. For example, if Boruto were to shirk his training or mock the importance of teamwork, which are fundamental to Naruto's view of being a ninja.
Maybe it's the high expectations that Naruto has for Boruto. Naruto is a hero, and he might unknowingly put a lot of pressure on Boruto to follow in his footsteps. Boruto could be scared of not being able to meet those expectations.
Some fanfictions might explore the idea of Naruto being betrayed by someone close to him. This betrayal could lead to a situation where he is caught off - guard and killed. It adds a dark and dramatic twist to the story.
Well, he might be really surprised. He could see different interpretations of his dad's adventures that he never thought of. It might make him understand Naruto's journey in a new light, like seeing how others view Naruto's growth during Shippuden.
In the 'boruto kills naruto fanfiction', a motive could be a power struggle. Boruto might believe that Naruto's power is holding back the village's growth or his own potential. He could think that by eliminating Naruto, he can bring about a new era of power in the Hidden Leaf. Also, it could be out of desperation. If Boruto is in a situation where he believes that killing Naruto is the only way to save someone he loves, like his mother or a friend, he might take such a drastic step.