Certain manufacturers use IR on their controllers for the simple reason that if the operator doesn't have line of sight to the machine it should stop dead and do nothing.
Not impossible to muck about with, but a damn sight harder than broadcast RF in much the same way as the Navy still use signal lamps (as Mr Corfield found on his recent exploits up north) - Point-to-Point/tight-beam, difficult to intercept and easy to encrypt. More people should be using it. Or embedding decent security in their products!