Why do you have to pay for your theory test

If you are one of those people who had to take a theory test many times you must be asking yourself this questions all the time. Why is it that you have to pay for the test every single time? Just imagine how more convenient would it be if you paid only once and than had an opportunity to take it as many times as you want. Well it sounds like a perfect dream but it will probably never happen. Why? If theory test would be free of charge (or would require only one payment for unlimited number of tries) people would be taking it as many times as they want to. That means that they probably wouldn't be prepared perfectly for their examination as there would always be a chance to sit it again. The result of that would be the time of waiting for the test. I think you would have to wait for it even up to six months and I am sure nobody wants that. Additionally the driver training centers would probably have to hire more staff to run the examination and their bills for power for example would be higher and higher. As you can see that kind of change would be a nightmare especially for owners of training centers and people wouldn't be satisfied as well if they would have to wait for the examination for a long time.