I think that for people outside of HN, that's OK. Not everyone trusts the open source community, or open source organizations.

If something goes wrong with something important, it's normal for people to want something or someone to blame. If that something is Apple, that's useful. If it's some rando on the internet contributing code to a code repository, it's significantly less useful to the ordinary person.

For the average person, entrusting Apple with their logins is a better option than using password1234 or some other coping mechanism. People know Apple. Nobody knows OpenID. It's the same reason people used to trust Microsoft (and many still do!) with their personal information. Microsoft is a known quantity.

It's like having a neighbor watch your pets while you're on vacation, or signing up with some random service on the internet to watch your pets. Those random services get bonded and insured for the peace of mind of the user. There is no such level of assurance from OpenID other than it uses the word "open" in its name, and as a culture we value the word "open" more than "closed."