I , Charles S. Fudge, hate many things. We all do. But let me tell two things I hate hate in writing.
1. The writer inserting themselves in.
I am kind of biased on this one, as everyone is vastly superior to me, but does any one really like this? What seems to happen is that they over power themselves to the point they're invincible and I know for fact everyone hates an overpowered character. I get it, if your just starting out and you don't know much about character development planet, like I do, writing about yourself is good way to start out. I just don't like it when all the time.
2. Characters being evil for no reason.
Okay, let me explain. All villains have motivation, like say killing the ,int to get his kingdom. However some villains are evil...just because. If it's some sort of mental disorder thing that makes them act like that, it's fine, because even those people have some sort of motivation. But some have the motivation "They're Evil!" So, why are they evil? I just don't like it.