Ok, so I feel a little silly.
I talked to a friend of mine who also owns the HTC One and I explained my Macro dilemma to him. Since he is considerably more well-versed in photography than I am, he let me know that a Macro mode won't necessarily effect the quality of the photo taken, but rather HOW the photo is taken.
Here's a test to show you what I mean.
Holding your camera in one hand, point it at a wall and let it focus in on it. Then, holding an arm straight out, place your hand in front of the camera. The Normal Shooting mode will struggle to focus in on the hand and/or the wall and will most likely focus on the hand...but it may not. To focus on the hand, you'd have to tap to focus before taking the picture.
If you switch the camera to MACRO mode, that "Tap to focus" step is unnecessary. When you hold something in front of the camera, it will automatically focus on the nearest thing to it rather than making you tap on it manually. So, do the same test and notice how much quicker the camera will focus in on the hand or other objects close to the camera.
This shooting method would probably be useful if you're outdoors or trying to take a shot of something with bright light obscuring the screen. Sometimes it's hard to tell if an object is in focus, so with the Macro mode you can rest assured that the object in the foreground will be what the camera is focusing on.