Open Office is a free office suite application working on different operating systems. In OpenOffice it is possible to open and save files in the .doc/.xls format (which is not based on open document format). OpenOffice allows to share files which were created using proprietary software. When such options exist, people (may be by ignorance also) will continue to use the .doc/.xls format using the OpenOffice suite, in turn creating files which are not based on open document format.
Well, on one hand it lets people to choose but on the other hand it also allows people to save in file formats that are not open. I think that after opening a .doc file using OpenOffice and then further editing it, the possibility of saving as .doc file must not exist in OpenOffice. May be in this way, atleast no files will be saved/generated which are not in open document format. In this way, people can be directed to use the open document format for files.