tl;dr +1 on keeping it

I also the see benefit of being able to turn a slideshow off/on without having to delete all of the images. Making this part of the settings is an easy way to do this that doesn't require any additional design or code to be written. Obviously if it were something we thought should be moved to the slideshow area in custo, this would require a new iteration since it's well outside the scope of what our initial project consisted of.