Earlier quoted context omitted.
Nearly every package manager I've ever used had post-install scripts. Most run as root, since that's what usually what the package manager runs as. It's not unreasonable: you're already installing software, which presents risks. If post-install scripts were not a thing, a payload could still run because you ran the software you installed. Or because the installer added it to auto-run. Or because the installer placed…
Nearly every package manager I've ever used had post-install scripts. You're collapsing two different threat models. The risk isn't that code runs, it's WHEN it runs. This worm spreads because npm install runs arbitrary scripts as you, automatically, just from resolving the tree. You don't have to build it, run it, or even import it. Opening the project in an IDE is enough. apt/dnf scripts run on packages a maintaine…
> You don't have to build it, run it, or even import it
If you just installed something with npm, chances are you'll be running it shortly, either as a tool or a library, probably minutes or seconds later. I imagine the use case of installing an npm package you don't plan on using or transitively importing, constitute a small portion of npm installs.