Here's a thought.
OOXML (Office Open XML) is criticized for being like a dump of MS Office's binary format: it is not altogether unfair because the aim was to completely represent the native format and much of that was simply not "semantic" let alone elegant.
But it meant that some technical at people freaked out when they saw it. Not just because there was no SGML-ish mixed content or tree structure, or because MS clearly did not have adequate internal documentation or documentation QA for the most mission-critical software of businesses around the world [[what is ISO but an organization to facilitate QA of technical documentation?]], but also because it had such a severe reliance on chains of links and markup structures that were alien to the HTML kids. (I will leave the ideological aspects out here.)
I wonder whether an objective cause to the subjective antagonism people felt towards it can be attributed to another factor: they intuited that to some extent OOXML was trying to do in XML what really would be better to do in JSON? I.e. moving around a big data structure.
(And I certainly don't want to exclude the possibility that some parts would be better in XML and others in JSON, i.e. a JSON-in-XML-in-ZIP approach.)
Regards
Rick
