IMHO the problem with D-Bus was that it was never small and utilitarian. They decided (correctly) to ignore all the engineering effort involved in performance and scalability, and put all that overengineering into the API instead.
D-Bus code is basically unreadable, as not only are the bus names heavily scoped (java-style) to avoid collisions, but also the interface and method names. A tiny python (or whatever) script to invoke a single method on a well-known object should be a one-liner but in practice lives over 6-7 lines just due to verbosity.
D-Bus types are inexplicably low-level for a "utilitarian" IPC mechanism, leading to a bunch of type conversion to do simple things, and a ton of marshalling code in the core. Javascript has shown us how far you can get with just IEEE doubles and UTF-8 strings, yet D-Bus suffers with a type model that looks more like C.
Yeah, I used to have a whole bunch of shell scripts to automate KDE 3 apps via dcop and then when dcop was dropped in favor of dbus, the complexity of the latter system discouraged me from porting the scripts.
Whatever technical limitations dcop may have had, its command line was amazing: space separated words and a emphasis on discoverability made it a joy to use
qdbus is an almost adequate replacement for that. It's still more verbose and a bit more difficult to pass some arguments (this is all from memory) than dcop was, but it's servicable.
right, nobody was ever intended to use the raw protocol details directly... those details were intended to support an API that looked like using in-process objects (well, perhaps in-process objects with methods declared as 'async').
D-Bus code is basically unreadable, as not only are the bus names heavily scoped (java-style) to avoid collisions, but also the interface and method names. A tiny python (or whatever) script to invoke a single method on a well-known object should be a one-liner but in practice lives over 6-7 lines just due to verbosity.
D-Bus types are inexplicably low-level for a "utilitarian" IPC mechanism, leading to a bunch of type conversion to do simple things, and a ton of marshalling code in the core. Javascript has shown us how far you can get with just IEEE doubles and UTF-8 strings, yet D-Bus suffers with a type model that looks more like C.