The Interest actually is the inflation. About 90% of the inflation goes to interest, and about 10% of the inflation goes to Content creators and Curators. And like Bitcoin, everyone knows that it is going to inflate, so every coin made doesn't actually inflate the value, because it is a prescribed inflation, and won't ever change. It won't inflate in unexpected ways, so the value of the coin is already based on that inflation and will not be effected by it.