I agree that transclusion, particularly based on byte offsets, is not very useful for the WWW. But the concept is much more useful than what the author suggests. Maybe you have heard of Ivar Jacobson's Objectory tool. I worked with it in the nineties in large projects and it was able to transclude terms and definitions wherever they were linked, even integrated in the text flow where they appeared. That was true added value and much more useful than tools like DOORS. I myself have implemented CrossLine, which I used for large project information aggregation, creating new documents with transcluded passages from specifications and minutes put into the most useful context. In CrossLine, the unit of transclusion is an outline item. Also Jacobson's tool had useful units. I think the failure of approaches like Xanadu was not an absence of meaningful transclusion use-cases; rather to identify and integrate the right units of knowledge.