This is usually true, but it is also true that some classes are graded "on a curve" and so grade inflation could hurt people who are honestly doing work. Also, cheaters tend to suck all the air out of a room. For example, my I.T. instructor designed a really nice oral quiz slide-show for the entire classroom. I found it a few hours before the class, I watched it in its entirety, and then when he tried to run it live, I spoilered all the answers before any other student could answer. I wasn't strictly cheating, but I wasn't being fair to my classmates' learning process, either.