I think you can make a case for Mr. Bates being the main character of the story, but I would still argue that Mrs. Bates is the true principal character.
You say that the story is built around Mr. Bates's attitude but I think that it is built around Mrs. Bates's feelings towards her husband. We see these feelings revealed through her talking about his absence.
To me, the story is about how dissatisfied Mrs. Bates has been with her husband. She feels that she has married beneath her and is impatient with him because of that. At the end of the story, she comes to realize that the problems in their marriage were her fault.
So Mr. Bates is central to the story, but only (in my opinion) as an object for Mrs. Bates's thoughts and feelings.