Not being on the hype train is a strange characterization - their last release was over two years ago, and its not like its just not popular in certain circles - there are less than 500 questions on SO for ingress verses almost 50k for postgres. Are you saying that it deserves more attention? As much as mysql/postgres/mssql and others in this article?
That's wrong. Open Source Ingres did it for many years too Of course unlike PG they are not on the Hype train ...