It's based on GraphQL, which is definitely not a hack like XML => language and currently catching on faster than a forest fire. Dgraph's derivation, GraphQL+- (for lack of better name) is a lot more powerful than Cypher or Gremlin. Both of the latter allow only returning lists of results; while GraphQL+- returns back an entire subgraph. Thus, all the relationships are maintained. It also allows expressing complex joins using a function like variable blocks; feeding results from one into another like you'd do in any popular language.
You can try running some complex queries with GraphQL+-, it might change your view.
http://play.dgraph.io/
That semi-declarative query language is hideous though. Reminds me of attempts to make XML into a programming language.