The big picture idea behind this thin-air-to-HBD conversion initiative (via high interest rates) is to attract the ignorant masses who would use the network without owning (too much) HIVE, allowing the core Hiveans (HIVE holders) scoop as much value as possible out of the network growth.
One day, the BTC is going to sneeze when we are close to the haircut threshold and not only HIVE gets the cold. HBD does as well (surprise to many). Having a BTC insurance fund solves nothing at that point. Its mission was to create an illusion of safety to get people onboard, not to help them out of trouble.
Everyone loses some money, and the market recovers sooner or later. The blockchain is not going to break because of that. All that happens is that the HBD holders who made 30% APR along the way (while HIVE holders were making 50-500%) feel cheated as they should have been protected against the crash. Well, no. They should have known better.