I'm not going to let people copy off my tests
Are people trying to copy off of you?
I am motivated to do my schoolwork, so they figure I will have the right answers.
That seems like a good idea. It's wrong to let people cheat off your paper during a test.
There's no harm in people copying my answers. It makes it easier for people to score well.
But people don't learn anything if they just copy off of someone else's test.