I want to make two points here. First, inconsistency and dissonance is, in part, a minor explanation of why students sometimes do not want to learn. Learning can mean facing inconsistencies and we know that inconsistencies produce dissonance. When the inconsistencies are large and when the students cannot solve the dissonance with learning, you as the teacher have a problem. Second, I still think a little dissonance is a good thing in the classroom.
Dissonance creates attention and interest.
It animates an internal drive to solve the dissonance-problem. Thus, artfully employed, dissonance can be an effective teaching tool. Here's an example. One very important aspect of communication is language and how people use words. Whenever I teach about how words have many meanings, I can start the unit off with this Thought Problem.