The perception of XML interoperability is inconsistent with the real world Microsoft Word format. As Gates is quoted, "Office documents, spreadsheets and forms can be saved in an XML file format that is freely available for anyone to license and use". Similarly, Microsoft protocols are freely available for anyone to license and use. The term "freely" does not imply "free of cost". In addition, with XML binary format now being supported, a vendor can easily lock in their XML documents so that they can be parsed only by their own applications (this is what MS is doing).
You make an argument about XML interoperability and conclude that somehow it is Microsoft that started it all. That is inconsistent with historical facts.
I am not a Microsoft fan, nor do I embrace the GPL. I run a research team focused on service oriented architectures. I hold 9 US patents and have been published (both book and literature).