I personally think SQL v. NoSQL is less useful of the two dichotomies, the other one being OLTP v. OLAP. In the end, SQL is just an API. You can put SQL-like interface on NoSQL as well (like SlamData for MongoDB or Crate for Elasticsearch).

On the other hand, OLTP v. OLAP (transactional v. analytic) is directly tied to use cases and has more profound consequences as far as technical decisions go (data structures, algorithms, etc.)