As I said, it doesn't need to be only public repositories. If I interview for containers, then I ask if they have something public on DockerHub, GitLab/GitHub registries. If the answer is no (happened just a few days ago), then I ask what they used. I expect them to say something like Artifactory, Nexus, a directory on a server or HPC, or just explain why they didn't need a registry. For me there is really no wrong answer here. But if they reply they don't have anything public, and have no idea what's a container registry, then that's probably bad -- this is what I think OP of this thread meant by eliminating candidates that are full of---.
> Where I live in Europe 90%+ of workers barring those currently in academia, have no public work because most companies don't publish their work, so you'd never hire anyone with that barrier.
My wife also works here, and she's a recruiter in a EU company, in cancer/research. Most applicants won't have things public in that case, but they can still explain things. If there is a candidate with similar profile, that managers liked, and they have a lot of good work, public, then it's up to managers. I just explain what I saw in the repositories, whether I'd work with the candidates, and the managers hiring choose based on risk for companies.
As you are based in EU, you probably have the same problem that the hiring process can be expensive for company, and risky if you eliminate candidates, and have to go back during the experience/trial period of candidates.