Earlier quoted context omitted.
Why is a pypi package better than a bash script? Or is it the URL shortener that concerns you?
Because a pypi package can be compared to a source. A piped bash script might change per-client or per-request.
The average person doesn't compare the source, and the average person doesn't read the bash script, for them it's the same thing.
For the person who wants to read the source, I'll argue that pressing backspace 6 time to delete "| bash" is _more_ straightforward than looking up the source for a PyPi package.
There's only a subtle difference between a PyPi account and a server (script hosted on Github?) being pwned.
Though yes, I do believe they shouldn't have used an URL shortener.