We can argue until the cows come home about the advantages of GraphDB vs Relational DB. We seem to be in agreement that graph-like queries are of great benefit.
And the fact is that until Neo4j, TigerGraph and the like came and started taking a bite out of the marketing share, Oracle and the like didn't bother to create a graph query interface. They were perfectly content with the status-quo and in no rush to innovate. And if they (Oracles of the world) manage to squash Neo4j's, they will go back to their complacent status-quo.