Yes, Don I was being a little tongue in cheek and I apologize for that. I was in a bit of a rush when I wrote that. Here's a fuller response.
Mac is almost certainly correct in claiming that mask wearing is less risky than no mask wearing with respect to community spread. But implicit in his response is that whatever risk remains is an acceptable one. It certainly is to him (and me) and probably everyone reading this. But one can imagine people for whom this lower risk would still be unacceptable. Such people might look at contra dancing as a selfish, recreational activity that during a pandemic endangers the health of the wider community. They would have a point. The only risk-free dance is no dance.
Now, fortunately, there are health organizations that provide guidance to all of us on matters of public health. We don't have to set policies based on the least or the most risk averse people in our community. We can look to these organizations for guidance. They don't set their risk tolerance thresholds at zero just like water departments don't set the acceptable parts per million of e coli in the water supply at zero. A certain amount of risk is acceptable (yay, we can all have a contra dance!). The premiere such health organization in our country is the Centers for Disease Control. In our dance community in Berkshire Count, MA, we decided to simply follow CDC COVID-19 guidelines, not reinterpret them or add to them, just follow them. Ever since our dance restarted last July, the CDC guidelines with respect to mask wearing in indoor spaces is that everyone should be masked if the community spread level of the virus is high (red). If it is low (green) or medium (yellow), certain individuals should be masked (e.g., the immunocompromised, those with a known recent COVID exposure, etc.) and anyone who wishes to mask, certainly can, but the CDC does not explicitly recommend that everyone masks. So, neither do we. If the community spread level is high, we simply cancel the dance (which we've never actually had to do).
We have followed the same guidance for COVID-19 vaccinations and boosters. The CDC has made it very clear that the purpose of the COVID-19 vaccination program is to prevent severe infections, not stop transmission, which makes sense given how poorly the vaccines have done at stopping transmission. So we don't exclude unvaccinated or partially vaccinated dancers from our dance because, as organizers, we are only concerned about transmission at our dance, not what health choices people might make for themselves.
- Jon Greene (Lenox contra dance organizer)