I have noticed that these things matter only when someone has been burnt by it once already. So before your class, nobody in their life had even bothered to check for plagiarism.

Had to fail the projects of 1/3 of the class in a community college because of plagiarism. Although to their credit, they at least put in some effort by shifting sentences around and re-drew other students' diagrams. They did keep the same node names and relationships between nodes, though.