I have't looked at it rcently but the last time I checked systemd was the 'nice to have' that was mandatory for some of the software I associate with a fully fuctional desktop which is not just a WM, DE (or not) and basic applications like xterm , vim, etc...But you are right. You can run the linux desktop like its 2007 without systemd on select distributions without screwing around too much...of course don't add new software without researching dependencies and default build options or you may end up with the worst of systemd dependencies anyway. At that point I just run KDE on FreeBSD.