As I have already explained my pro GitHub arguments in the question, I'm going to rebut the con arguments I mentioned here:
- Answer does no longer directly contain all relevant information, one could argue that it is a link-only answer.
I say this is not true because all answers that advice installing a software X from anywhere would then be link-only as well - they only contain instructions how to install and use that program, but not the program itself, right?
- The link might die and the script may no longer be found. That's the main reason why link-only answers are not allowed.
I say there is no higher risk of a link to a GitHub repository to become obsolete than of a Launchpad PPA to get deleted or a package to become no longer available in any other way. GitHub is safe and will not quit business within the next years.
- It requires an additional click to get the needed information.
I personally prefer three additional clicks to download a file over a long click-and-drag to copy all the code from the answer's code block and nothing more. There are also wget or git commands that download the file directly - as simple as running apt-get install to get regular software.
- You need to leave the site to get the needed information.
So what? If you can trust Stack Exchange, you can also trust GitHub. It's not a shady download site but the world's most famous place where open-source code is stored.