Correct, but the point is still a subtle one in practice. Clearly the "separation" is easiest for those who have a very clear idea of Wikipedia's mission, and plenty of experience of the type of writing Wikipedia aims to include (and how people react to the other kinds). 

The guideline is meant, as such things generally are, to convey to editors what the expectations the site has of them. 

In talking to academics, I tend to say that Wikipedia articles are meant to be "good surveys", and lead the discussion onto the ground of how surveys could fail to be good (tacitly, "or even to be a survey"). I'm sure the points about self-citation and skewing the content excessively to a single school of thought are comprehensible in that context.

The distinction between what you are permitted to do, and what it is advisable to do, remains. Most ordinary folk have no real means of knowing what they may be getting into when they edit Wikipedia, and stray marginally in the direction of self-promotion.

Charles