The researchers studied the progress of the disease, without treating it, for 40 years.
Prior to the availability of penicillin in the 1940s and 1950s, the researchers couldn’t have treated the men even if they wanted to. Even after standardized penicillin treatments were available, it wasn’t clear that the patients could have been helped.
Reality, via Wikipedia:
The first antibiotic to be used for treating disease was the arsenic-containing drug Salvarsan, developed in 1908 by Sahachiro Hata while working in the laboratory of Nobel prize winner Paul Ehrlich. This was later modified into Neosalvarsan. Unfortunately, these drugs were not 100% effective, especially in late disease. It had been observed that some who develop high fevers could be cured of syphilis. Thus, for a brief time malaria was used as treatment for tertiary syphilis because it produced prolonged and high fevers. This was considered an acceptable risk because the malaria could later be treated with quinine which was available at that time. This discovery was championed by Julius Wagner-Jauregg, who won the 1927 Nobel Prize for Medicine for his work in this area. Malaria as a treatment for syphilis was usually reserved for late disease, especially neurosyphilis, and then followed by either Salvarsan or Neosalvarsan as adjuvant therapy. These treatments were finally rendered obsolete by the discovery of penicillin, and its widespread manufacture after World War II allowed syphilis to be effectively and reliably cured.
Not only is this choad writing for National Review, his mishegoss now appears in the NY Post. Apparently his book "I know you are but what am I?" gives him the gravitas to appear in a daily newspaper.