No, it's not. If Debian had a community-maintained repo of additional packages, the same thing could happen there.

The fundamental problem is having something that has very loose oversight and next to no controls. That may have worked in the past, but in the day and age of constant supply chain attacks, it's a major liability.

Rolling release has nothing to do with this. It could just as well be a PPA in ubuntu or any deb repo for debian or similar.

Makes sense.