I feel that, (training sectors aside) although most of the FOs I fly with are very competent, there are a few who just don't know the job properly, and need some help and 'pointers' from time to time. Although there's nothing wrong with giving sectors away to them, they require a more 'kindergarten' approach.
A good, well-informed, FO, who knows the books well and can think for himself in terms of the 'big picture', should not be subject to frequent interruption.
A borderline-competent FO may well have a different (and unsatisfactory) experience.