What's wrong with self-referentiality?

I hear the above term used with ease, of being "self-referential" in one's work. It is closely connected with the encouragement to "construct your own visual language" etc, so if this unique, personal visual language becomes opaque to the point of no-one understanding it but yourself, is this then "wrong", and is it contravening the "rules? In an increasingly sophisticated and visually literate world, surely the post-structural theory of "intertextuality" as the ability to cross-reference texts with visual clues, would result in quite a lot of self-referentiality. Was Picasso being self-referential in his Artist and Studio series, or when he painted a parody of Velaquez's work in Las Meninas. I suppose one could say that he had a historical precedent in the genre of life drawing for his Artist and Studio series, and of course he was looking to the past masters of Spanish painting in Velaszquez. Gunther Kress and Theo van Leeuwen would seem to be of the opinion that even so called self-referentiality does not refer to nothing, and that the semiotics of hermaneutics can usually decipher even the most elusive of signs. (Kress G. Reading Images: Multimodality, Representation and New Media) iiiD%20Kress:%20Reading%20Images%20Multimodality,%20Representation%20and%20New%20Media.webarchive. (date accessed7/5/2010.)