As a long time teacher at several levels of education, it would be lovely to have the students come to class for the sake of learning. To know that the students were there because they desired to gain all of the knowledge that you had to offer them would be the best of all worlds for both teacher and students.
Unfortunately in America at least, this is not the case. In high school, a good per centage of the students go to class because they are made to go by officials and parents. Their purpose there is to get a grade and move on. If a student likes a particular subject, he may work and learn for the sake of learning. However, this does not...
always happen when the student likes the material.
At the college level where students have to pay for classes, expectations might be different. This is not the case; in fact, many times the student just wants to eek by with a "c" and survive the course.
What is my point? If you do not have some kind of examination to gauge the learning of a student and to force him to study, he more often then not will do nothing in the class.
Having been in classes where the professor only required attendance to complete the class, students slept and sneaked out of the class. Nothing was learned or accomplished.
I wish it were possible to do without tests, but unless something changes, they will be required.