One of the reasons I hate apt, is that after a while of configuring your desktop, removing unnecessary packages, etc, it will start annoying you with "packages that are no longer necessary". It will ask you to do apt-get autoremove. I once did it, and found out it had removed a number of things such as GDM (I uninstalled GNOME and installed XFCE), to system utilities such as File Roller and Synaptic. At least it should have a warning message that it might break system usefulness, it makes it look as if the long list of packages are not necessary AND no longer being used.