I feel like this is the main distinction.
There are two issues here
- the model needs to be carefully prompted (goaded) into copyright violation, so it is instigated to do it by excessive quoting from the original
- the replicated codes are usually boilerplate, common approaches or "famous" examples from books; in other words they are examples that appear in multiple places in the training set as opposed to just once
Do generic codes, boilerplate and API calls deserve protection? Maybe the famous examples do, but not every replicated code does.