The type property

https://www.w3.org/community/xformsusers/wiki/XForms_2.0#The_type_Property

"The datatype is associated with the string-value (as defined in [XPath  
1.0]) of the instance node. It can be applied to both elements and  
attributes, but not to instance nodes that contain child elements."

In XDM, the type is associated with the node. Is there any objection to  
using that definition instead?
https://www.w3.org/TR/2010/REC-xpath-datamodel-20101214/#ElementNode

What is the objection to binding a type to an element with children?

Steven