The teaching style used at EnfoS starts from the principle that teaching should be seen as helping someone to learn by making it learner based and error based. Error based because it is not much use to teach something that isn't a problem for the learner while on the other hand, each error should be seen, by learner and teacher, as a challenge to overcome. This asks for especially adapted, modulated material.
From the point of view of a learner as well as that of a teacher, I always felt there was serious lack of explanation of why certain forms should be used under certain conditions. Explaining at least as much as possible of the whys, is among the attempted improvements.
Because these are language teaching-learning resources and not scientific communications, plausibility of the explanations for the intended public is considered more important than factual accuracy.
A language can be seen as a communication tool. Like any tool, it fits a purpose, the purpose to communicate. It is also possible to see a language as a toolbox where the multitude of language elements, like grammar forms and idiomatic expressions, are the tools in the box. Following this analogy, it makes sense to explain language learners when and why a certain tool is more appropriate in one case, less in another and not at all in yet another case.