Adding into what others have said about the industry standardizing on the knuckle couplers, Miller platforms were also rather expensive because Miller demanded significant royalties. They also required some maintenance. Janney's coupler wasn't necessarily better for passenger work, but it was good enough and it was cheaper. The cost of Miller platforms as well as the design being intended for passenger cars specifically meant they weren't used on freight equipment as a rule.
Link and pin couplers had a lot of slack which resulted in telescoping. Some derailments happened due to sudden deceleration (such as for a bridge) causing the rear cars of a long passenger train to slam hard into the leading cars and pop off the rails. Also the older style of couplers did not automatically uncouple when cars turned over, quite often pulling other cars over with them and making a derailment worse than it needed to be. During the post civil war era litigation and suit settlements were a major cost of doing business for many railroads, in some cases their largest individual cost. Miller advertised--sometimes correctly--that even as expensive as his platforms were, they'd pay for themselves simply due to lessening injury settlement expenses.
Edited 1 time(s). Last edit at 01/02/2021 01:10PM by James.