Unlike bitcoin[which has no use value, only trade value] xrp is needed to use the functionality of the ripple network.
Well by the same token Bitcoin has also got use value because it speeds up transactions if used as fee and is also needed for some transactions to ever go through.
That's an interesting interpretation however that's still a trade value -- the bitcoin is merely changing hands from node to miner, so realistically that's still an optional trade, and hence still kind of a trade value. That's splitting hairs though so I'll admit you have a point.