Edit: oh wait I read your comment wrong. I thought you were saying not to take it out of the context of the image when you were saying the opposite. Ok now I get it!
In some parts of Mexico, the end caps are called the “suegras,” the word for mother-in-law, because no one wants them. I think it’s meant to sound like “sobras” which means leftovers.
I doubt the end being there makes much of a difference, it’s already sliced and air can easily get into the cracks. Plus you’re always taking the front piece which has supposedly had the most contact with the environment, so it doesn’t have much of a chance to go bad. Furthermore by reaching your grubby fingers around to sneak a middle piece you probably pose a bigger risk of contamination to the loaf.
I’m not convinced this method keeps bread longer until it’s put to the test.