I'm not going to bother with quoting statistics, etc. Half of the people in this country believe this is a deadly disease that you must avoid at all costs, and the other half believes it's just a more severe version of the flu, and you will get better. No amount of posting, shouting, brandishing statistics, will change anyone's mind, and that's fine. But this:
I hope I'm misunderstanding you Sue, but it sounds like you're blaming one or more of your regulars for not being careful, and for giving it to you. I personally know someone who was very very careful, and still got it. From where, who knows? The grocery store? Pumping gas? Picking up a package delivered at their door? Passing by someone on the sidewalk and the virus came through the masks anyway because masks, while good, aren't 100% effective? Being careless isn't the only way of catching this thing, and you just have to be prepared to deal with it if you do catch it.