Striking a Deal?

So I have been reading some blogs that teachers have (I am getting addicted here people!! You may see me on Intervention or somethig). In just a short amount of time I read that not one, but TWO teachers strike an interesting deal with their students to behave in class. This was the deal- the student behave and the teacher PASSES THEM!!! What????!!! Maybe I am totally naive here but I don't see how it is right to tell a student that they will pass a class simply because they behaved. One example said the kid couldn't read (at the middle school level) and thus couldn't do the work and was a distraction. Well, is passing them helping them at all? Is that the best deal the teacher could have made? I am hoping these are once in a lifetime deals during the first couple years of teaching when you will do ANYTHING to have good classroom management, but even then I think it might be a little unethical. Am I going crazy here???