Perhaps the themes or characters weren't engaging enough. Maybe it was released at a time when there were many other popular manga stealing the spotlight. Or it might not have been available on popular platforms where people tend to discover new manga.
Well, there are so many fanfics out there that it's easy for some to get lost in the shuffle. Also, with new shows and stories constantly coming out, people might move on from Naruto fanfics.
Well, it might be that your story's title and description didn't catch people's attention. Also, the quality of your writing or the lack of a clear plot could be factors. Another possibility is that you haven't interacted enough with others in the community to generate interest in your work.
Perhaps the story is set in a chaotic or dystopian world where memories are easily lost or manipulated. Or, it could be a plot device to make the character feel isolated and drive the story forward.
It's possible that you didn't share the story correctly or your internet connection was unstable when you posted it. Make sure everything is done right and your connection is good.