Purpose-built or task-specific tools are just that: designed for a specific task and purpose. They usually work exceptionally well for that specific task, and marginally well, poorly or are downright dangerous when used outside of the design scope.
The tactical world is overrun with gimmicks, useless bolt-on trinkets, and various snake-oil peddlers. Some of these items are ridiculous, and only good for a laugh by those who might need to rely on their gear in the real world. Other items could actually hinder functionality and become a risk to life and limb.