I have heard this point of view, but admit that I struggle to understand it. These formalisms have types and convey structure and relationships between types. Is there a more suitable formalism for data-models that you make use of?
An object-oriented formalism, in UML, uses XML for interchange.
But irrespective of my lack of understanding of the 'errors of my ways' (something I am trying to overcome), my concept of leveraging data-models in cost-effective ways, as I tried to give some examples of, is my key point. So data-models as XML do seem to me to be a fertile ground, for this "simplicity stack".
Regards
Steve