It's not a 1930s rule, it's universal and stressed in the ATC learning academy. In fact a trainee can fail an exercise if it isn't done. It's similar to braking distance in a car. The overshoot is more critical today than in the 1930s with higher closing speeds. A go around combined with a warning indication and reduced manoeuvrability makes things hard enough without a light aircraft being there and the pilot replying "say again" to a critical instruction.