Judd, not just that, but if this procedure was applied intelligently, the system was armed on receipt of takeoff clearance. So, it served as a useful confirmation that clearance had been received. Pressed TO/GA and nothing happened? Check with tower that you’ve received your clearance... A rare intersection of good HF science and aircraft operations.
Boeing’s method is like carrying a hunting knife tucked in your belt, when you’ve a perfectly good sheath for it the other side. There are no arguments whatsoever for arming until ready to get airborne.