Problem is zsh is not omnipresent like bash is.
I'm sure that if you use zsh you also use Plan 9, code in D, write LuaTeX in Emacs and wear a monocle.
I don't use Plan 9, code in D or write LuaTeX, but I do use Emacs and wear a monocle. The last two are not a coincidence as the first (arguably more adequate substitute for God), invariably leads to the latter, most excellent eye wear.
And a note to my Mac friends : "Using csh is like trying to type with your feets[sic] (if you're used to zsh or ksh)."
In fact I find zsh much easier for beginners and people who don't master the arcane intricacies of *nix.
I always have fun to see junior guys trying their way around such systems.
You should use different software or customizations when it's a good trade-off, not because everyone else is or isn't doing it.
I don't think it's that much of a problem. My local machine is zsh, my linux servers run bash, my solaris hosts csh. Where ever I am, I just adjust to the local environment.
shopt -s globstar
rm **/*.swpThe OP's first argument is: for all operating systems Bash exists. Which, while also untrue is and unrelated to whether ZSH has features or improvements that Bash does not. OP's second argument is: all ZSH users also program in D...., which I won't even bother with.
For what it is worth, I use both Bash and ZSH. Their usage and knowledge there of is not mutually exclusive. The only issue I've encountered with using ZSH is that most build scripts expect to be ran from Bash and will run into issues when that is not the case sometimes, so I open Bash before running the command if I happen to be in ZSH at the time.
If I based my tool choices on popularity instead of their appropriateness for the problem domain my work flow would look much different as well.