REST has the same problem as object oriented programming. It's too skeuomorphic. Lots of web applications are wrappers around conceptually monolithic resources, so it's convenient to use a protocol that makes that assumption. But as soon as you need to nest resources, or perform some action that has nothing to do with CRUD, or do just about anything interesting, the metaphor begins to fall apart.

(That's also why OOP has all these "patterns." Many are just attempts to cope with the "object" metaphor falling apart. "Is" an AttackingRock a Monster, or "is" it an Obstacle? Hmm...)