TBF most commentators now recognise that no-one had tested Rapier under the conditions that applied - a rushed embarkation, cross decking , a long sea journey and then deployed on a unprepared hill top in the middle of nowhere and having to work in combat conditions in a a few hours. The fact it eventually worked at all was quite good.
Several other systems didn't work as everyone hoped - but that's what happens when you face the realities of combat rather than tests, exercises and simulations