English encyclopedia articles should be understandable by non-specialist native speakers. If the topic or concept cannot be given a generic overview readily understood by a layperson, it is not a topic to be included in a general encyclopedia.

[[L'Hôpital's rule]] clearly fails this metric.

(The counter argument - that a specialist encyclopedia may cover its subjects at any depth - is a [[strawman]]. A specialist encyclopedia has a targeted audience; it is in fact the definition of such a work.)