[jimbokun]

"One argument is that XML is better than JSON for use cases like XHTML, where you heavily mix tags and content."

Yes, this is true. The point of using XML is when you have data where you know the structure of some parts, but not others. This is true of most things that begin life as prose, and then have some structure added to them later. It is a point between "bag of words" information retrieval, and SQL queries, that requires a different approach.

"I get the feeling XML wasn't really made for this case, though, it was made for the JSON-like case."

No, this is false. XML is awful for the JSON like case. What would make you think that XML was created for it?