I agree, I still see this one with new F/O's. They have been trained to only change to STD when within 1000' of transition, a level bust in the making.
Some operators use this "new way of thinking" and I agree it causes more problems than it solves. The theory is that ATC might ask for "level passing" or give an amended clearance to level before the transition layer. In those rare instances, I say just reset the altimeters back to standard or QNH if you need to.
Being an American, I don't read ICAO pubs much, perhaps this "new" procedure is buried in some recent training standard or something.