That must be one of the most important points in aviation training. It isn't deliberate, but at some point or other a student will do something that left unchecked would be the end of it. I've had two such encounters in less than a week and I've only been an FI for 6 months...
One involved low level graveyard spiral dive in darkness. The poor old PA28 was doing 140 knots indicated! The other was a scarier cross control turn to final at 400 feet after "engine failure" and close to stall speed. They should weld the rudder pedals to the floor.... This particular individual didn't realize the danger and would likely have killed himself if alone...