'It is written'.....
'Bold' pilot who try stall without sufficient altitude to safely recover....
Maybe Not live to grow 'old'......
It may well be an 'arbitary' figure, but then so may 2,000ft, or 2,500ft. or whatever.
This figure has been around for a loooong time - and I have forgotten any 'legal reference'.....
Others will no doubt supply words of greater wisdom...
I had student in the 'old days' who objected to the time consuming climb back up to 3,000ft following manoeuvres which involved some height loss.
I wonder where he is now...??