NNTP is a general-purpose, globally meshed & distributed, channelized, eventually-consistent pub/sub bus. With optional ordering, GC, and replay semantics, and

NNTP is a general-purpose, globally meshed & distributed, channelized, eventually-consistent pub/sub bus. With optional ordering, GC, and replay semantics, and robust and stable implementations of both client and server protocol available in a variety of language bindings. So the only real surprise is that it isn't everything's preferred loose-coupling substrate, but we do love reinventing the wheel.