I'm thinking it had something to do with a Hornady safari to Africa and the use of the 416s on Cape Buff that didn't go smoothly.
That, in my view, doesn't make them bad bullets, just not up to the intended task and pricing goal perhaps.
I tested some of the early ones before they became expensive:
These were fired into big moose bones and recovered in wet newspaper. The three on the left are 500 Interbonds, the rest 405 Woodleighs, all fired from a 45-70 Ruger #1. The bullet on the far left is simply a wet paper expansion. The jackets on the gold colored IBs do seem a bit brittle.
Accuracy potential seems okay - these three shot groups were fired at 75 yards:
They were a great bullet and real bargain at the price they introduced them. Once you raise the price, you also raise the expectation.