These were people who actually had risks.
ARS symptoms are very generalized, meaning
they would be present for a million other reasons (flus, other viral infections, colds, allergic reactions, even anxiety). They are not specific to HIV. It's not like a specific symptom that would point to an illness/condition, like the bullseye marking in Lyme's disease. ARS symptoms just are not reliable, and they could be present in a person for SO many other reasons.