I have a home folder. It's just empty. To answer your question though, no createHome = true is not in my configuration.nix file. I could dump all that, but this is a fresh system. It's clearly an issue with the NixOS installer. I tried it on completely different hardware just now and have the same problem. I solved it by running this series of commands.
xdg-user-dirs-update
gio set ~/Desktop metadata::custom-icon-name user-desktop
gio set ~/Documents metadata::custom-icon-name folder-documents
gio set ~/Downloads metadata::custom-icon-name folder-download
gio set ~/Music metadata::custom-icon-name folder-music
gio set ~/Pictures metadata::custom-icon-name folder-pictures
gio set ~/Videos metadata::custom-icon-name folder-videos
gio set ~/Templates metadata::custom-icon-name folder-templates
gio set ~/Public metadata::custom-icon-name folder-publicshare
xdg-user-dirs-gtk-update
I guess it's fine, but not ideal. I could see that confusing the shit out of a more casual user.