Why did Microsoft develop OpenXML, how does it feel about negative market sentiment and does it see standards coexisting in the market?

Microsoft has been taking flack ever since it released the OpenXML file format to accompany its next iteration of Office. And it's being fast-tracked through the ISO standardisation process.

The heavily negative sentiment, largely from the open source community, doesn't focus as much on Microsoft's submission of OpenXML to the ISO committee, but rather on the fact that a file format standard for productivity suites (an open source derivative at that) already exists in Open Document Format (ODF).