This is a great topic to bring up cause its actually a good list for storytellers on how not to tell a story!
Me personally, I stop reading if
The Story is too slow paced and doesn't get to the gist quickly.- for me the story has to at least let me know what I'm in for in at least the first chapter if not the first upload or else its not worth my time.
BAD dialogue- this could be subjective, but there is such a thing as flow when it comes to this kind of stuff. Some authors just copy and past stereotypical phrases and call it dialogue when it truly doesn't feel genuine in the slightest.
Lazy Artstyle - I say lazy because art style is subjective so bad doesn't really come into play for me. But lazy art is the worst. If the author has a specific style and then just doesn't focus on it anymore or doesn't clean up than it puts me off for sure.
No Theme - I might be alone in this but I love a story that is thought provoking even if its a comedy. Without a good strong central theme (no matter what it is) I can't invest my time in that story. It feels useless.
Cliche - Anything that does not have a unique concept and simply rides off the back of already successful works (fan fiction), or simply adds more monotony to a genre of work without innovating will most likely get boring quickly for me. I don't know I guess I just like cool concepts in storytelling!
Thats it for me, but this thread for me is a good way to gauge peoples tastes and am thankful you brought this up!