So is the dollar, the euro, the pound, the yen. Well, until the moment when the corresponding central authorities decided to print new trillions of these "good" currencies. How is XRP different? Oh, the central authority promised not to print more than 100 billion? Is that what makes XRP a good currency?

Transaction fees have to be paid either in BTC or Ripple IOUs (as per BTC/IOU exchange rate). Introducing XRP is what will kill the whole idea of Ripple. XRP is just another private currency like AmazonCoin!