The identifiers are namespaced so that if you have differing vocabs with the same property names (or datatypes), you can distinguish which one you're talking about.
Your proposed transformation means that Property lives in the example namespace, meaning it has a completely different interpretation, which is specific to the example namespace.
*: (before someone pulls me up on this, it's not 100% correct)
Still leaves a bad taste in my mouth (you can't have two on the same element, for example. unless you can whitespace-separate them? and still, what if your value contains a colon?), but I guess less so.