While your frustrations are understandable, I think it is also important to consider the school's side here. This is not just about a ton of people gathering together. The bigger issue is the fact that people are travelling from all over the country and even internationally to come to the interview, quite substantially increasing their own and other people's risk of getting sick.
I also would not classify a bunch of eager premeds as the "the most conscious individuals regarding the virus". At this point, even medical students, who've had far more training in PPE and disease control, are being asked to refrain from many activities.