Fair point that. lightdm got itself installed on my Debian laptop a ways back, it's sufficiently non-annoying that I've left it be. The GNOME desktop manager bugs the crap out of me. I'm old-school enough to still somewhat like xdm, though I've used wdm (windowmaker / GNUStep) and kdm.

I interact with any of them so infrequently that it's really not a concern.