I didn't mean it in a sarcastic way. I just meant that they have not assigned enough resources/people to do a proper review of the legal status of all files. Or even enough resources to update the files. That is just the simplest explanation for why the headers haven't just been cleaned up. It is fun to assume there is some grand conspiracy to rob the general public, or LibreOffice in particular, of some useful code. But much simpler to assume IBM just doesn't care and hasn't thought much more about it. They seem genuinely unaware that until they clean up all headers first nobody, even other Apache hackers, can do anything with the code.
IBM seems not very interested in the symphony code base anymore, they now have the (proprietary) IBM Docs (cloud based office) project. And clearly some people IBM assigned to the former symphony/apache project, like Rob Weir, have different priorities than helping out with cleaning up the legal uncertainties of the contributed files.