The thing with the interest rates on HBD is that it's something that we all pay in the future. The interests are in addition to the organic hive inflation and it's bascially money printed out of thin air. Since every hbd can be converted to hive, every hbd in interests represents 20 potential hive tokens that could increase the supply and push price down. That's why we need some interests to keep people invested, to avoid to supply shock and at the same time every interest point we pay, increases the future potential of inflation. It's a difficult line to walk.