The worst outcome is that individuals may have sensitive information in their medical history that could be poorly received by their social circles if it becomes public. In extreme cases, this could even lead to threats on their life.

Consider this: the same argument could be applied to our endeavor to safeguard the secrecy of voting. What is the worst outcome if everyone discovers who you voted for?

Such conclusions are inherently biased because we are unable to accurately evaluate the importance of these very existing protective measures in a civilized society.