Not sure I completely agree with Centaurus this time. Most times a stall should be and is a non-event, agreed, but St Murphy, the patron saint of students will ensure that somewhere, some day, when approaching the edges of the flight envelope, either a student will do something stupid or an aircraft will spring a surprise on you - at which point it is very comforting to have a bit of space beneath.
Full disclosure, I'm not an instructor, but once managed to cause a little damage to our respective underwear by being overenthusiastic in correcting a wing drop with rudder in an unfamiliar aircraft - the resulting roll reversal was pretty impressive and we'd lost the thick end of 1,000' by the time I got it tidied up. Did I mishandle it, yes certainly, but doubt that I'm alone in doing that.
Point being that if we'd started at 1,500' on the basis that we shouldn't lose more than 150' in the recovery, the trees would have been looming during the recovery, the perfect scenario for more hamfisted behaviour like an accelerated stall.