I think it is mainly because `fish` is incompatible with everything. Most `bash` scripts runs fine in `zsh` (`zsh` has even a `bash` compatibility mode, not nec

I think it is mainly because `fish` is incompatible with everything. Most `bash` scripts runs fine in `zsh` (`zsh` has even a `bash` compatibility mode, not necessary generally because rarely `zsh` and `bash` diverges), no `bash` script runs fine in `fish`.