Does the XML syntax have an underlying data model?

Michael Kay wrote:

> The Namespaces in XML spec came from the XML Core working group. 
> As with the XML spec itself, the group chose (in my view unwisely) to
> define a syntax with no underlying data model. 

I read Michael's words to say:

	XML has no underlying data model.

Isn't the XML Infoset considered to be XML's underlying data model?

I am looking at the specification for the XQuery and XPath Data Model (XDM) and it says:

	The [XDM] data model is based on the [XML] infoset.

That seems to say that the XQuery and XPath Data Model (XDM) builds on top of the XML data model (XML infoset).

Am I reading Michael's words incorrectly and the XDM specification's words incorrectly?

/Roger