REST+HTTP are not without their issues, but I'd argue they've been successful in allowing numerous heterogeneous applications to speak with each other, in a reliable and standard fashion for many years.
Compared to more complicated protocols such as SOAP, COBRA, DCOM, etc...REST+HTTP is as reliable and ubiquitous today because of its simplicity and generic nature. Adding features and utilities for a particular aspect (i.e. "social") would serve to weaken the protocol, not make it better.
The argument that the HTML+JS+CSS side of things has turned HTTP into an application environment is a bad thing is puzzling. Besides, what is the point of a content transport protocol if not to provide valuable services and use cases on top of it? We have TCP and UDP to push bits around...