I think you're misrepresenting RMS. In that article, he is mostly saying that hardware cannot be properly copyrighted/copylefted, and then pushes for open access to hardware interface specifications.
The closest to "not advocat[ing] free hardware" I can see in the article is where RMS states that there is (at that time) no way to download hardware the way we download software. correct me if I'm wrong.
Well, if I misrepresented him then certainly not intentionally. However, please have a look at this talk by rms where he addresses the question of free hardware in more detail:
http://www.linuxtoday.com/infrastructure/1999062200505NWLF