Washing with soap disrupts the endocrine function of the skin, which doesn't fully recover for a couple days. It's not a matter of bad chemicals in the soap; stripping away the natural oils messes up synthesis of things like Vitamin D. The article didn't even touch on this and instead just talks about bacteria.
Frequent use of soap is going to impair the skin's barrier function and leave you more susceptible to infection. You should really only be soaping up as needed.
Personally, once a week is fine for me. I'll just rinse off as needed the rest of the week, which in winter might be once.