VERY true.
In fact, I have a personal theory that true "San Francisco bathhouse" behavior never existed for long in previous human history. Rapid spread of infectious disease would quickly wipe out any group that engaged in it.
Only in the late 20th century did it become feasible, as antibiotics and other treatments kept the participants alive and fornicating despite their contracting multiple diseases.
Ironically, this advance in itself allowed for the rapid spread of AIDS, as the behavior that allowed for the rapid spread was only possible (for more than a brief period) due to medical technology.