I have always believed it came about after a mid-air collision over New York just after the first jets entered service.
16 December 1960. A United DC-8 was inbound to JFK (then known as Idlewild) from LAX. A TWA Super Connie was inbound to La Guardia from Columbus. The DC-8 began descent rather late and hence came down fast. Also it only had one VOR operational ( long before glass cockpits and sophisticated nav systems). While trying to get two radials from a single VOR the DC-8 crew overshoot their waypoint at nearly 400kts and collided with the Super Connie over Brooklyn. 128 + 6 on ground killed. After that the US introduced two requirements: speed limit of 250Kts below 10,000 feet and all large airliners must also be equiped with DME as well as VOR.
But I could be wrong!