There seems to be two points in this comment, one talking about the development of PostgreSQL and the other talking about the usability of it.
PostgreSQL remains one of the most mysteriously difficult common DBMSs to setup which is unfortunate, but since the advent of MongoDB they've adopted all the ease of use features that are warranted from it. Developing a quick-and-dirty product prototype on postgres is a breeze and bootstraping constraints and data-integrity to it afterwards is trivial. I am really not seeing any reason to start a new app on MongoDB exclusively at this point, start off in a strong DBMS like postgres and if you end up needing MongoDB-style document storage you can always branch to it later, but using it initially is a case of premature optimization, there is no need for it.
PostgreSQL remains one of the most mysteriously difficult common DBMSs to setup which is unfortunate, but since the advent of MongoDB they've adopted all the ease of use features that are warranted from it. Developing a quick-and-dirty product prototype on postgres is a breeze and bootstraping constraints and data-integrity to it afterwards is trivial. I am really not seeing any reason to start a new app on MongoDB exclusively at this point, start off in a strong DBMS like postgres and if you end up needing MongoDB-style document storage you can always branch to it later, but using it initially is a case of premature optimization, there is no need for it.