It's based on Cypher, which is a query languages for graph databases. The author/s probably thought the data is more graph-like than relational.
I’d disagree and say that Kubernetes is much more relational that graph based, and SQL is pretty good for querying graphs anyway, especially with some custom extensions.
This does make more sense though.
For example, to find all friend of a friend or friends of a friend of a friend: `MATCH (user:User {username: "amanj41"})-[:KNOWS*2..3]->(foaf) WHERE NOT((user)-[:KNOWS]->(foaf)) RETURN user, foaf`