The reason was that many men died who could have been saved. Even when penicillin was available, the doctors neglected the men real treatment. The experimenters deceived the test subjects, by not telling them the truth of their condition in the first place. In addition, because of the lack of oversight and formal protocol, nothing was actually confidential.
The worst of all is the blatant prejudice that continued all throughout the experiments. Diversity is key to understanding anything in science. It is essential to test a wide variety of humans to understand the minute details of the human mind and body. The fact that these experiments were targeting black men, illustrates the lack of morality from the United States at the time.
In conclusion, The Tuskegee Experiments is a scar that will forever remind scientist why we uphold moral and ethical standards. It is astounding that the experiments on a few hundred black men, with untreated syphilis, could go on for so long. Because of the coercion and deception of the test subjects, consent forms were mandatory. It is sad to look back at these experiments and know that nothing was gained that could not have been known through moral means. There is not one single thread of knowledge that humans must ascertain if it means others have to