I haven't looked deeply into this particular project but I agree with you: the hypergraph data model seems to add too much complexity for too little bang compared to a generic graph model. The Neo4j graph database:
is based on generic property graphs. We sometimes get requests for hypergraph features, but we've found that the real-world problems are always solvable through a normal graph. Either way, it's very nice to see more open source graph databases out there!
-EE