IBM Restraint More Likely Out of Fear of Examination of its Own Standards Practices
As former Ecma president Jan van den Beld wrote in his blog, IBM has long dominated ISO and other standards processes and has used a lot of questionable tactics along the way, including in the OOXML debate. IBM doesn't want a full fledged investigation of standards processes, because it is IBM rather than MIcrosoft that will take the biggest lumps in that process. More importantly, it might lead to changes that will limit IBM's longtime ability to manipulate standards bodies.
http://janvandenbeld.blogspot.com/2008/04/hypocrisy.html