I often think the existence of CSS can be seen as the strongest criticism of XML: when designing a language to store styling attributes for HTML, they used their own heirarchical format instead of another SGML-derivative.
If it is such a problem for you, I would suggest coming up with actual solutions instead of the Grandpa Doom visionary "prediction" you've offered which is of no value.
It's neither a good rendering medium, nor a good language to describe the structure of the data.
XML was initially thought of as a simpler SGML, but when it took off it started to be used for all kinds of data including data which are not based on human-readable text at all. XML is fine for markup, but needlessly verbose and complex for non-markup languages.