Are you a developer yourself? If yes, you should now already that developing is moving forward not backward. Stuff changes all the time. Also developers inside Jolla knows that. Python3 not backward compatible with 2 Qt4 not backward compatible with Qt3 Gnome2 not compatible with Gnome1 X11 not backward compatible with itself. And in case of computer languages: New languages comes and others dies. and so on... If you are a developer and dont like movement you will get into trouble thats for sure.