[uncomputation]

I don’t see the abuse here. Sign In with Apple is only required if you already support Facebook or Google or another third-party social sign in. If you support only email and password, that’s fine. If you do support social sign in, presumably you do so because then you don’t have to worry about passwords and stuff. Well, this is exactly the same. I don’t see why it makes a difference.

[jeroenhd]

The abuse is that Facebook won't refuse updates to your customers' devices if you choose not to opt into their SSO, but Apple most certainly will.

The problem is not the social sign in aspect, but that fact Apple forces you to implement it if you use their competitors' service.

Had Sign in with Apple not been mandatory, but merely something customers would ask developers for, then I'd consider the framework to be fair game. This simply isn't that.