How many Ursacks have you personally seen fail?
Somewhere around 8. That's more than the total for all of the other canisters combined in 20+ years of them being around. And back to the main point of food reward. The original criteria defined failure as getting food. With a cannister, that usually means a catastrophic failure and access to all the food. With the Ursack, that includes (!) punctures such that food drips out or whatever. That means that the wily bears will keep trying to get into Ursacks and keep hanging around camps in the hope of doing so. That's considered a failure for those reasons.
