Funny enough I frequently have the opposite problem, justifying repeatedly why Cassandra is a bad fit for relatively short lived, frequently updated data (tombstones, baby).
The specific data that went into Cassandra in our case was basically immutable. (And somehow, IIRC, we still had issues around tombstones. I am not a fan of them.) Cassandra's tooling left much to be desired around inspecting the exact state of tombstones within the cluster.