Here is an indication of situations when applying REST is not appropriate:
When all artifacts that are affected by a possible change are owned by the same project (e.g. stored in the same source code control repository) then REST is not a suitable style.
An example of this is an application that contains a database component for its private use. Usually the database schema is stored in the repository together with the source code. If you face a need to change one, it is easy to change the other (from a developer coordination point of view).
The general take away from this is that artifact ownership can be used as an indicator for how appropriate a candidate style is.
(Consider how much the Unix command line benefits from the uniform API pipe and filter style: Completely decentralized developers can contribute components (grep, awk, sed, less, sort,..) without even engaging into agreeing on how the components talk to each other). The artifacts that make up the unix tool box are maintained by many different parties all over the world.