Even if the 99,9% of times all the applications released through the official repositories are reliable and perfectly working, sometime a buggy package might get installed on our systems after an update. With a few steps we can rollback to the previous version taking advantage of the feature made available by package managers and repositories.
Whether you are compiling an application yourself, or you are just using a binary tarball archive, having a method to notify the Desktop Environment about the installed software to have a shortcut in the system menu or just register it to handle a certain MIME type, it is for sure a comfortable adding. If that method is also widely adopted among several, if not the major part, of Desktop Environment available, then it becomes a must!
Often we rely on CLI applications or small scripts to elaborate files and most of the time we would like to have quick access to them while browsing our filesystem with a file manager like Dolphin. Luckily, an highly configurable environment like KDE, overcomes this issue allowing every user to populate the contextual menu.