Yes, artificially complex.

No one genuinely interested in document openness—be it for document workflows, publishing automation, content archiving, or future-proofed documents—would have done it that way.

Maybe it was as simple as dumping a simplistic re-encoding of its legacy binary format into XML and ramming it through standards organizations. But yes, there was malice aforethought and a classic Microsoft playbook in motion: embrace, extend, extinguish.