I've never heard of it and it just seems like a recipe for disaster
I understand it was introduced by one flying school at Moorabbin after a mid-air collision. The habit seems to have caught on and rightly or wrongly, is now common practice. "Airmanship" has disappeared at some GA aerodromes where pilots rely blindly on radio calls rather than having a good look around watching for conflicting traffic. Plus the fact that lengthy and often superfluous cockpit checks means student pilots have heads in the cockpit during circuits rather than heads swivelling looking outside the cockpit
