But, to answer your question, Stallman is interested in the freedom of the end user to modify the code and redistribute the modifications to that code freely. He has been almost freakishly consistent on this topic for the last 200 years, restating that stance in a multitude of articles, interviews and talks.
Anything that ultimately results in code being 'locked down' and unavailable to the end user to modify and then redistribute, he has a problem with. This includes the public domain.
To me, however, it seems like the goal of GNU/Free Software is usually conveyed as maximizing freedom in regards to software. They themselves stress that word "free," and point out that it's "free as in speech, not as in beer" without emphasizing that they really just mean "free for the end user to see and modify the source."
In my opinion (and yes, under my personal definition of "free") the GPL does not maximize freedom and instead is exactly like other copyrights except that the restrictions it places on software are perhaps different than other copyrights. I personally do not think that software should be covered by "property" protection laws, because I think the analogy of software as property is fatally flawed and leads to serious contradictions and ambiguities. Also, on the more practical level, I do not think that intellectual property protection for software is necessary for a thriving and innovative software industry.
It is freedom as in speech, because it is the freedom for users of code to take that code and use it to express their own ideas, and to redistribute that expression to their friends and anyone else who may be interested. In that context, code is literally a form of speech, and the software an expression of an idea. Under the freedoms provided by something like the GPL I can take someone else's idea, change it to suit myself and redistribute that change.
The GPL clearly does not attempt to maximize the freedom of developers or distributors who wish to deny end users the freedoms that the GPL provides.
Again, this is ground that seems to be covered over and over. It is hard for me to believe that someone like you, who is clearly intelligent, has clearly thought about the subject and discussed it previously, has truly never had it explained to them, or has entirely failed to understand the distinction. I hope this has helped a little.
Still, I find the GPL to be more restrictive and less free than the public domain, and therefore less desirable. I take issue with the way RMS and GNU uses the words "free" and "freedom" because I see their philosophy not as a principled desire for freedom, but rather merely as a desire for certain restrictions on freedom (granted, a different set of restrictions than proprietary software licenses).
I think that "The Free Software Movement" is an unfortunate title. Not only do they have to constantly remind average readers of their definition of "free as in speech, not as in beer," they also should be clarifying their definition of "free" for people like myself who believe that freedom is an utmost concern. Perhaps a better though less catchy title for their movements would be "The Publicly Available Source Code Movement."
'people like myself who believe that freedom is an utmost concern'
which freedoms matter to you, and for whom? without context your statement is pretty much content free.
IME almost everyone believes that freedom is an utmost concern, even Brutalog, the Despotic Dictator Of Zoogtzargle believed that he was fighting the good fight for freedom.
The interesting differences seem to lie in the context under which they define the term.
Regarding practicality, RMS claims that the GPL forces companies to open-source software that would otherwise by proprietary, thus opening up the information contained within to everyone, for their use and improvement. In reality, I see more cases where the company instead recreates the software using a proprietary (or, if we're lucky, permissive open-source) license (PySide and Clang come to mind).
Here's an example of this
http://arstechnica.com/old/content/2007/10/european-copyrigh...
The GPL, or CC (or some other license) sidestep this issue by working within the nearly universally accepted legal framework of copyright vs. the Public Domain. In Stallman's view, because PD cannot be guaranteed to use the force of law to maintain his view of freedom, it's unworkable for his purposes.