A CA system is not a system that doesn't have partitions, it's a system that works under the condition that there are no partitions (ie. it is a non-partition-resistant system).
But that is not a choice with distributed systems, unless as soon as a partition happens the system shuts down immediately. That is it effectively disappears and never re-appears again. But that's not a CA system then?
Or saying that it is not partition resistant is also difficult because the system in case of a partition will do _something_. The typical choices is that it either responds to clients (trying to be AP) or it doesn't (trying to be CP).
That is why I understand CA systems as equivalent to the belief that "partitions can't happen". Which I think is unrealistic.
Yes, it's a pretty much useless system.