As I said kenscot, I am not criticizing you, but pondering just like you. When these new cartridges came out, the ammo manufacturers had to "tool up" to build the new cartridges. This must have in itself cost a fortune, and the cost was passed on to the consumer.
Being a hunter for over fifty years, I too have used the 2506 extensively, and like the cartridge, but after loading several thousand rounds of this cartridge over the years (since 1971) I didn't see the advantage of the shorter action in the field. On the bench perhaps, as a shorter action has less "flex" on cartridge ignition, but then again, it would depend on how tight the bolt locks up, as to whether even this would matter. The 2506 "as is" when tuned properly and with the right loads can hold it's own in any organized shooting sport off or on the bench.
I believe the manufacturers ALSO made a judgement call (evidently a bad one), that believed any one whom would buy a "new cartridge" rifle, would also want the latest in "new cartridge" technology.
My opinions on failure are just that. My opinions. Short light rifles built on standard rifle actions such as the 2506 have been around for years, and one is not gambling on a new cartridge making it or not. Another opinion. I'm a boring guy. I only bet on sure things. New cartridges have came and went over the last 100 years. And these went. For what ever reasons, the demand was too small, and just reason some are called wildcats, but some continue to hold on to them.