Why do people still insist on doing this? That script sudo installs a random .deb/.rpm from https://d3sqy0vbqsdhku.cloudfront.net - are you going to notice if someone hacks the site and points to a slightly different url?
This is not much different from running random .exe files that you find on the internet...
And what alternative do you suggest? Spamming the download page with 100 different instruction links for each OS and version, where each download page just links to a tar.gz/deb/rpm that still can execute arbitrary code?
There's only three if you check the script out - Mac, .rpm and .deb. Is it really that hard to set up packages for three things? Depending on what's in there, it could also just be a node package.
Do you know what you're saying? Three binary packages. Three different systems that you have to learn separately.
Have you ever made a .deb or .rpm, let alone a YUM or APT repository? The documentation is horrible. The .deb documentation mentions all kinds of abbreviations and obscure commands... fakeroot, autobuilder, pbuilder, dh_make, devscripts... good luck with that if you don't even use Debian as your primary OS. RPMs are slightly easier though by much. And this is only about generating the .debs/.rpms themselves. Good luck learning all the complex packaging rules and dependency specification rules.
What if you don't have a Mac, do you have to fork over $1500+ to buy one just so you can create a .pkg?
For the same reason that people run random .exe files that you find on the internet. The problems are rare enough that people can easily think them away. And the people giving the advice think "well, this is a safe resource, so there aren't problems asking people to do this", because people aren't very good at contemplating their own failure.
I'm not saying that's a justification. I'm just saying why people do it.
This is not much different from running random .exe files that you find on the internet...