CP is a CMS. The reason why Posts are seen as default content type in the dashboard is because WP was initially created as a blogging platform. Content/Data should be defined by the user. Hence, I propose that there should be no default post type in the fresh install/dashboard, and that a simple UI for registering CPT's should be included. It can be called "Content", with a submenu of "Create Content Type". The reason for still registering as CPT is to adhere to WP ecosystem and database structure. I know... this can be achieved using plugins... But the being a CMS, there should be a way to distinguish one content from another at the core level.