That is true. I have nixos and multiple debian variants running in my house. Nix has a semi-functional graphical interface for modifying that file, but I don't want to start editing my .profile in order to get sway to work. My current focus is on a different project right now (and will be for the foreseeable future). Experimenting with wayland isn't on my TODO list right now, especially with the notice in the nixos manual and wiki.