The first thing we have to know is what it is NOT ROCK CMS. ROCK CMS is not a CMS. We can not compare it with Prestashop or Wordpress because it is not conceived to be Plug&Play, i.e., it is not created to be easily installable and working for any purpose. Is this a positive thing? Yes, it is, because the final product obtained using ROCK CMS it is not a "hack" but a "bespoke suit".
Then, what is the purpose of ROCK CMS if at the end the work is a "bespoke suit"? The admin pages layout, the common pages layout (like error pages or information pages), a lot of functions, a lot of extensions to support emails or PDF, etc. All of these things and more are shared between different projects. The goal is save time reusing things done previously (and, in consequence, save money).
Therefore, ROCK CMS can be understand like a template. This template will be molded to the customer needs. Even if the customer does not need any changes in ROCK CMS, some features can be better adapted to his needs, or something can be deleted to not hinder.