What concernes me is that the article is strongly biased in the sense, that modern developments of non-relational databases just get ignored while ranting on their state from a few years ago. Schemaless databases do support full ACID transactions (MongoDB, ArangoDB), with some you can also enforce a schema and not everybody loves SQL. So having competition even on the query language-side, can only improve the status quo.

Yes, thinking about your data model will for sure increase your understanding of what you are actually doing... and every professional developer is doing this as well when choosing a non-relational database. Anythings else would be stupid.

For me the article rather shows that the modern developments in non-relational databases do affect vendors on the relational side of the spectrum. Otherwise, it would not make sense to invest so much time in writing such a long article.