Mainly I meant that I no longer see it recommended on the Arch wiki, which I think is where I first learned it. But it looks like that might be because Arch now compiles systemd with lingering on by default (or something similar to that, I'm probably using the wrong term).
Linger does more than just keeping the session open after logout. It also means that the session gets started automatically on boot, which is necessary if you want to have systemd units for that user autostart. Case in point, the PulseAudio setup on my homeserver: https://github.com/majewsky/system-configuration/blob/2f93ff...
