But lets admit that distros of Linux have become idiomatic. Its reasonable to give a caveat when describing any Linux procedure. This is not an Ubuntu issue at all.
In fact, what's the point of different distros if they aren't idiomatic?
It's incorrect to assume that a shell script that uses tools like xxd and awk is distro-specific. Almost every distribution ships the GNU coreutils and other GNU base tools. It's going to work on basically every distribution. What makes distributions unique is their package manager, release and security philosophy, amount of cruft, etc.
Even the same distro line but different versions may have significant issues. This is why every build on top of Linux (e.g. Android) calls out a particular kernel version. Even a particular version for the build machine. Because things like command line tools differ over time. Versionology is a whole universe of hurt on Linux.
That's the cost of supporting code that is constantly being updated, you need to start freezing versions and backporting fixes. Also, I'm not sure what command line tools you're referring to as "differing over time". Kernel version freezing is mainly fear of new code (or out-of-tree vendor patchsets that depend very strongly on the kernel ABI which changes every few months -- but that's not user visible). Sure, if your system never changes anything you don't need to worry about software versions. But there are many other problems with that.
In fact, what's the point of different distros if they aren't idiomatic?