Actually D-BUS and DCOP are much better than COM, if Microsoft ever looked into COM like tooling in other platforms, instead they keep rebooting the ATL like experience while ignoring how others have improved upon COM.
XPC and Android Binder are also two other examples of better tooling in this area.
I never dug into D-Bus deeply enough, but as a user, for me it caused one big problem: press PrintScreen for > 1 second, have Spectacle hang itself and take dbus with it, making the whole OS inoperable. Reboot Linux, notice post downvoted by linux fanboys.
XPC and Android Binder are also two other examples of better tooling in this area.