Your phone uses various methods for focus, though as humans are humans, people complain if the click to take image delay is too high. So to satisfy people, you can take a picture even when the phone knows it doesnt have focus. If the phone is having a moment and struggling or someone just presses it too early, you get blur. The idea behind that setting is it should remove 'user error' and delay the picture taking process until the phone is sure.
If things are still blurry after changing that setting, then yeah I'd say something is up.
The idea behind those Samsung apps. Samsung doesn't like people rooting their phones. So they provide really powerful tools to tweak how the phone works. They just aren't installed by default as most people would set them wrong and complain