Your solution didn't use Keyboard Maestro any more than mine did. You bailed out to ~15 lines of JavaScript, which wasn't in the Wiki any more than Unix tools are.
Finding the answer for a shell script to do the job could be found by using the first answer in google for "reverse lines shell". There were actually about 5-6 different ways of doing it on that one page alone.
Oh come now.
That is a common fear expressed by people who don't really know the command line and who have only heard horror stories, but the likelihood of you doing anything resembling "tremendous damage" to your system by accident is infinitesimal.
There are a few commands that can do damage: rm obviously, and even rsync if given the wrong syntax. But those aren't commands that a novice is going to go anywhere near.
Could you typo rm and accidentally delete a file? Yes. Could you accidentally delete or overwrite a file with Keyboard Maestro? Yes.
You know what's far more likely? That you could want up tomorrow and find your hard drive has died. That's why we have backups.
If you are processing text -- the topic at hand -- you can find incredibly powerful tools at your fingertips via the command line. Ignoring or refusing to use such a versatile tool in your toolbox due to lack of knowledge or fear would be a shame. Passing that phobia on to others is a disservice.