RE: Why does the default namespace not apply to attributes?

>Wouldn't it be more intuitive and improve readability to have both of the
attributes in a different namespace, instead of one attribute being in no
namespace? 

The XML Namespaces spec has been with us since 1999. There are lots of
things that one might want to do differently given a chance, but it's etched
in stone and there's no prospect of changing it in fundamental ways. XML
Schema has to work with the base specs as they exist, not as one might like
to redesign them (even if everyone were to agree that you were right, which
is unlikely).
 
Michael Kay
http://www.saxonica.com/