My first thought was related to this as well: Perl is _always_ installed, and based on Python's popularity (compared to Perl, at least), I'd assume that Python also was installed by default?
That's an honest question, btw: I use Perl quite a lot, Python not so much (at all). :)
Plus of course if you want to use (pure perl) cpan dependencies I wrote http://p3rl.org/App::FatPacker and http://p3rl.org/Object::Remote to make that easier.
Why do you link to p3rl.org? And, more importantly, why do you link to something that doesn't exist?
For servers it's less common, but enterprise systems never cease to amuse me.
Still, zx isn't as nice as Ruby, which has backticks for calling shell as part of the language. So, you don't have to have a separate package installed, just the ruby runtine.
But Perl is even better! Just like Ruby, it comes with backtick shell execution build-in, but unlike Ruby Perl is ubiquitous and is pretty strict about backward compatibility. So, your scripts will just run on all machines you have, no matter what distro you use and how old the machine is (within reason).
[1] https://github.com/google/zx/blob/3.0.0/test.mjs#L30-L33
Most images will either have bash or ash installed. ash, being lightweight, is the choice of alpine and related distros.
Later shells came in and filled some gaps. OpenBSD still has ksh by default. Linux distros had bash as their /bin/sh.
It was a terrible idea, as I now had 3 problems instead of 1:
1 - Writing scripts, plus:
2 - Installing Python in every host that needed to run those scripts
3 - Maintaining Python and the necessary dependencies up to date in each host / container.
(2) and (3) are trivial when done just once in your own computer, but end up being a huge time sink for larger heterogeneous environments with (possibly) network and security barriers. Moreover, if you are using containers, installing Python will make images unecessarily large.
Granted, I'm not a JS person, but I imagine one will have the same issues.
Even though bash has its shortcomings, I really appreciate how low maintenance it is as long as you keep scripts small and sane.