Why specialized destroyers miss the general-purpose test

Where do unsuccessful destroyer designs most commonly go wrong?

They become too specialized, emphasizing either the shield or the spear so strongly that the ship cannot perform the balanced general-purpose destroyer role.

Overspecialization can leave a destroyer strong at either attack or defence while weakening its other responsibilities. Soviet destroyers provide examples of capable ships optimized for one side of that mission. German destroyers illustrate a different problem: cruiser-like gun ambitions could produce weapons the hulls could not use effectively and that caused problems when fired. Such compromises undermine the adaptability expected of a general-purpose destroyer.