The text contrasts settings of address to an acute listener (khiṭāb al-dhakī, خطاب الذكي) and one whose understanding requires more support (khiṭāb al-ghabī, خطاب الغبي). This is an analysis of audience needs, not a license to belittle a listener.
A grammarian may understand a condensed technical term immediately; a beginner may need its definition and a worked example.
An explanation can be grammatically fluent yet contextually poor if it is too obscure for beginners or unnecessarily repetitive for experts.