I think the central issue is your average PPL student should not get a say in how the aircraft is operated. You are the qualified instructor and PIC, he/she are there to learn. I politely but firmly tell all my students that at all times the aircraft will be operated my way. I always try to explain what I am doing and work hard at staying consistant. I refuse to put up with students who argue and question everything said to them. my personal tactic is to ride them hard pointing out everything they do wrong. They either get better or get lost. acquiring a reputation as a demanding instructor is not necessarily a bad thing as it tends to attract the hard working motivated students and discourage the tossers. Of course as a part time instructor who instructs for fun I have more options than a full time club instructor. The final caveat is the instructor should be able to explain everything he is doing. Unfortunately there are hours builders instructors who learn the minimum and do not make the effort to do the job right. Being a good instructor is not a function of hours in the log book it is entirely the choice of the instructor. Sorry end of rant
