Assaf writes about, among other things, REST as a simplifier of development against an existing system:
REST plays the same role as open source and open APIs: It eliminates tooling and vendoring as artificial barriers to adoption.
As a result of building a website for a Torchbox client, I came up with a Drupal 5.x module to query the Postcode Anywhere and MailBuild webservices (if they look like an unlikely mix, don’t worry: they’re not coupled together generally, so you can use one without the other). I’ve been meaning to make it live for ages, but never got round to scrubbing the client’s data out of it. Now that we’ve unearthed the module for other work then I’ve finally finished cleaning it.
Web architects must understand that resources are just consistent mappings from an identifier to some set of views on server-side state. If one view doesn’t suit your needs, then feel free to create a different resource that provides a better view (for any definition of “better”). These views need not have anything to do with how the information is stored on the server, or even what kind of state it ultimately reflects.