I mean that for all practicing data analysts that I know, XML is a pain in the ass (parsers, xpaths, etc, all to get it into a csv that you can import), while nice ascii text is easy to work with.
If you want metadata, a well written narrative paragraph along with a code book is INFINITELY better than embedding the metadata in the data.
Furthermore, a lot of supposed metadata in XML is just dross like "<column>blah</column>".
Finally, all the crap in XML way ups the signal/ noise ratio; if you do need something that maps to a complex data structure use JSON or something rational. Such needs are not very common in data analysis, in contrast to web applications; data analysts use multiple tables and are usually pretty close to relational databases and SQL (even if they don't call it that).
If you want metadata, a well written narrative paragraph along with a code book is INFINITELY better than embedding the metadata in the data.
Furthermore, a lot of supposed metadata in XML is just dross like "<column>blah</column>".
Finally, all the crap in XML way ups the signal/ noise ratio; if you do need something that maps to a complex data structure use JSON or something rational. Such needs are not very common in data analysis, in contrast to web applications; data analysts use multiple tables and are usually pretty close to relational databases and SQL (even if they don't call it that).