Skill of the Craft
One of the skills learned by technical writers and trainers is the concept of a target audience. Target audiences might posses certain skills or presumed to have no related skills at all.
In many professions and vocations this presumed minimum knowledge level is known as “skill of the craft.” Such people are presumed to know certain things. For example, writing a how-to or procedure for an electronics technician presumes skills in using certain test equipment. Specific instructions about using test equipment often are not provided nor deemed necessary. The targeted audience of users are presumed to have these skills.
Even with specialized equipment in which additional training is required, specific instructions about that equipment usually are minimal because the technicians performing related tasks often are presumed to have obtained that training to perform those tasks.
Writing for a general target audience presumes no skills at all. Often that means more verbosity with instructions and guidance. With software that also means discoverability. That is, users should be able to discover how to perform specific tasks based on well designed interfaces.
More often than not, distro maintainers and desktop developers do not abide by this simple focus. The target audience is almost always fellow geeks. Usability testing is limited to fellow geeks in some IRC channel.
The “skill of the craft” of users, that is the skill level of all users, are presumed to be skilled computer users. To be terminal users.
This is another reason Linux desktops continually fail to impress non technical users.