Oracle is like the C++ of databases; Postgres is like the C#. Oracle is ugly and complex, but it can be made to do amazing things that no other RDBMS can do. Postgres is really fast out of the box for 90% of most use-cases, but it still can't do the things Oracle can.
I was actually thinking of exactly this analogy earlier. It holds also in that a lot of people use C++ because they think they need it but they could in fact use something simpler.
