Bugs like these are nowadays only getting fixed in GStreamer 1.x (hopefully they get fixed at all).
Not only does Phonon ensure KDE's ABI stability promise, it also means that people like me can simply avoid such bugs by just using the VLC back-end.
VLC simply works. It works since ages.
VLC also is my movie player of choice – longer than GStreamer even exists. So why not also use it as Phonon back-end to listen to music in Juk?
Gnome is heavily involved in the development of Wayland and Weston.