Well, the truth is I've installed SDDM because of this article. It was interesting for me particulary about why KDM is not going to be used in Wayland environment because it's has been decided to let KDM as it is. KDE decided to not rewrite KDM using QML or creating new from scratch. While kde plasma workspace is going on the way to Wayland, it's just so silly if it doesn't came with any login/display manager.
For some people, not using LightDM is about the license. Again, Canonical seems more and more phenomenon in the opensource world, and I tend to avoid Canonical. I don't like glamour and famous thing, it tends to corrupt or corrupting others. That's why I don't use *ubuntu. Don't argue with me, because I'm not trolling your decision using *ubuntu. For that reason I'm also not using LightDM, but choose SDDM for the display manager, replacing KDM.
