I can't adequately convey what I think is Fielding's position on how machines should interact with RESTful systems, but I will convey my understanding of the purpose and intent of his thesis:
REST is a characterization of the Web architecture itself. It's not an alternative WWW, it is an abstract description of the principles behind the WWW. You can see this theme in Chapter 4 of the thesis in which Fielding characterizes REST [1].
> This chapter presents the requirements of the World Wide Web architecture and the problems faced in designing and evaluating proposed improvements to its key communication protocols. I use the insights garnered from the survey and classification of architectural styles for network-based hypermedia systems to hypothesize methods for developing an architectural style that would be used to guide the design of improvements for the modern Web architecture. [...]
> The early Web architecture was based on solid principles--separation of concerns, simplicity, and generality--but lacked an architectural description and rationale. The design was based on a set of informal hypertext notes, two early papers oriented towards the user community, and archived discussions on the Web developer community mailing list. In reality, however, the only true description of the early Web architecture was found within the implementations of libwww (the CERN protocol library for clients and servers), Mosaic (the NCSA browser client), and an assortment of other implementations that interoperated with them.
> An architectural style can be used to define the principles behind the Web architecture such that they are visible to future architects. As discussed in Chapter 1, a style is a named set of constraints on architectural elements that induces the set of properties desired of the architecture. The first step in my approach, therefore, is to identify the constraints placed within the early Web architecture that are responsible for its desirable properties. (internal citations elided)
By "distributed hypermedia systems", did he really mean "alternative browsers for alternative WWWs"?