Setting Expectations About CloudKit

I don’t see how this is true. While it’s technically possible to use the public data for group collaboration, it’s only the code in the client app that enforces this. CloudKit has no notion of groups.

It would be irresponsible to use the public data for private group collaboration.

Neither of the two apps mentioned as example — Glassboard and Wunderlist — should use CloudKit.

Very good points. Possible, but not responsible.