I was always against zsh as default. I also think our implementation with pkgfile is problematic … zsh isnt exactly posix-compliant … we implement it through things like Konsole profiles instead of login $SHELL, which is weird - but is apparently because zsh breaks things if set there … so I also say if it is not good enough for TTY then it is not good enough for terminal emulator default … etc.
See tangible example of issues: