Several comments have indicated problems with the cardinality restrictions. Some suggest that the spec is too restrictive (having only one full name, for example). Others say it's too liberal (because you can have a class with no attributes at all). A Core Vocabulary is a set of terms, not an application environment, hence the following proposal. Furthermore, cardinality has no meaning in linked data with its open world view.
Proposal: Remove all discussion of cardinality from the core vocabularies.