DBus is not Ubuntu-specific. You can find it in almost every distribution and runs on Windows as well. If you accept generic questions about programming with DBus, then you must accept generic questions about programming with Python, C++, GTK, Qt as well.
One thing is asking questions about programming with tools really specific to Ubuntu or about Ubuntu customizations. A different thing is asking purely generic questions about stuff that is in he Ubuntu archives.
"How do I communicate to Unity via DBus?" looks to my eyes as an Ubuntu-specific question. "Emit signal for GIO.DBusProxy in python?" instead seems a question similar to "How do I write 'Hello World' in Python", except that it lacks details and should be closed as too localized: how is the signal handler implemented? Are we sure the OP is sending the parameters correctly? Has anybody tried to reproduce the problem? The fact that nobody has asked these questions in the comments is a clear signal that nobody is interested.
I may seem radical, but the reason why I do not want to see such questions on AskUbuntu is that very few people (perhaps nobody) is going to answer them here. The OP will have much more luck asking on StackOverflow and Unix & Linux. My aim is to give people a faster chance to receive better answers. If you care about your users, then you should move their questions there.
