True, but the lack of a clear distinction also seems like a weakness in the specific DSLs rather than a weakness in the format. HTML has (with some exceptions) a very clear distinction between them: attributes are for metadata, elements are for visible page content. Android's XML draws a similar distinction, with attributes used to describe properties of a view and elements used to describe child views.

(I do concur with others who have noted here that the "elements" versus "attributes" distinction makes XML a poor choice for serialization, but XML as a serialization format isn't really the issue here.)