Ah, well, I'm probably one of those people.
I use Cetaphil on my face, too. A wise dermatologist recommended it to me almost 25 years ago, when I started getting acne after after the birth of son #2.
I use Ivory soap on the rest of my body; come to think of it, I don't use soap on most parts, just the armpits, and "sweaty" parts. I do sweat profusely. But it's not a conscious decision, it's just the way I wash.
The thought of not using shampoo seems creepy to me. I can go a day without shampooing, if I wet my hair and use product, but after that, it's not nice. My head itches, too. My hair is already source of irritation to me, which is why it's short. In fact, I grew it longer last year and cut it in the fall. I still have side bangs that look great, but require a flat iron. After a ski or ride, it's gross. So, next hair cut, back to the pixie. I've used Bumble and Bumble products for about ten years and I am happy with them.
OK, back on topic. It's great if you have the time to make your own soap, but I am getting a picture of a woman stirring a pot in colonial times. I seriously do not worry about this kind of stuff too much. My skin does get dry in the winter; I use Cetaphil lotion, along with a few other things, but it seems to be related (I know) to wearing wool. Even the merino seems to bother me. Guess I'm just a princess, but I've tested this out in the last week and as soon as I ditch the wool, the itchiness goes away.