Did you more than glance at the page you linked to? That article totally supports Walter's point. Not only are the freedoms to change and to redistribute changes excluded from the page you linked to, the page also refers to the essay "Free Software and Free Manuals", in which RMS explains why freedom is not as important for documentation.
???This article tell that documentation should be free (redistribuable and modifiable).
"The criterion for a free manual is pretty much the same as for free software: it is a matter of giving all users certain freedoms. Redistribution (including commercial redistribution) must be permitted, so that the manual can accompany every copy of the program, on-line or on paper. Permission for modification is crucial too."
It tell that freedom to modify is not important for political text (which is not documentation). I understand this argument; what freedom would be provided by doing this? It would simply abuse the reader by letting him think that what he read reflect the opinion of somebody else while it is not true. For example; I understand the fact that I cannot say something like "Debian is about proprietary software and affiliated with Microsoft" since making such claim is simply lying.
Debian has in my opnion a tendancy to make confusions. It's true that documentation is not software (although it is related) and it's even more true that political texts are not documentation. The DFSG speak about "software" and in the description about "program"; anyone with a good dictionary will know that a "political text" is not a software. If Debian want to change this, they should change the DFSG and make that clearer; but maybe they do not have the majority to do that.
Olive Olive