Critically they promise "by a certain time" as well. Surely with so many miles you are aware of the "significant disruption to my travel plans" aspect to getting compensated for a service that they failed to deliver.
Plane crews timing out on the tarmac at midnight forcing everyone aboard to lose a day of travel is not a "sob story" it is a systemic and purposeful optimization on the airline's part, a gamble that they can put up enough customer service phone menus and hoops that they only have to comp a small portion of customers whose time and money they've misappropriated.
ETA: my example above is to point out that even in the common failure cases airlines are awful, and as OP shares, even worse in the rare engine failure case. Yeah, they don't directly control that the engine failed (unless we start talking about how lack of maintenance and overworked mechanics contribute to that, which we should, and is under their control btw) but a hundred bucks for being stranded in the jungle is an insult no matter how you slice it