Well, art style and art competence are very different. I'm gonna give different answers depending on perception.
Art style should give a mood that suits the story. So long as it does, it's doing it's job! If the story is light hearted and emotional the art will normally be easy and gentle. If the story is gritty and dark the art will normally be more intense and have complex lighting.
Art style will normally appeal to the audience your story is written for in the first place. If it doesn't, maybe it's just not very well thought out?
Art competence will put off an audience, yes, because if your characters have bad anatomy or your backgrounds aren't well thought out, that's not just the art style. It's an example of poor competence. If your art doesn't look like you spent time on it and like you know what you're doing then it will be off putting because it will disrupt the flow of the story.
That's my two cents anyway.