Because giving the information asked for can lead the DIYer to do work without a genuine understanding of what's going on, and that is unacceptable.
Being pragmatic, should it not read?
Because giving the information asked for can lead the DIYer to do work
correctly even without a genuine understanding of what's going on, and that is
safer.
I think I know the probable reply so -
thinking logically, it does seem rather incongruous if, on a DIY forum, we cannot answer questions because they are too simple, because surely, the simpler the question the more 'non-competent' the questioner must be.
Therefore all questions regarding lighting circuits (as in this case) are to be ignored because if the questioner were 'competent' and knowledgeable about electricity he would not be asking.
This leads on to the point of how complex and involved does the subject have to be before we can answer.
Having deduced that the poster is very well qualified and expert in the field. We decide that we shall answer his query,
but wait - he doesn't know how to do what he wants to do. He must be a bit thick.
Next!