Very common. RESTful architectures always give rise to this type of pattern. For example, you fetch a user id, and then you fetch all the blog posts by the user then you fetch the comments for the blog posts.
Very common in poorly designed RESTful architectures. Hypermedia-style APIs take care of this. [0] The performance advantage of lightweight payloads to an SPA gets trashed by network latency otherwise.
I don't think the structure of the response would be the dictating factor for a "poorly designed RESTful architecture". This response format no longer makes things RESTful because it lumps together so many different models. This format is more suited for command/presenter pattern (orchestration).
