That general approach was so common. It really is sad.

One of the really bad effects of modern society (american especially) has been conditioning us to think of ourselves as these independent entities separate from nature and from our actual physical communities & people. We just interact with those things when we require their resources, etc. Transactional relationships happen.

One effect of this is, of course, not being considerate to those around you. But as your example shows, some people are so bad about it that it's not even a question of deciding whether to choose their own convenience over the safety of others. Considering the risk to others never enters the picture in the first place. When asked about it they would answer something like "my health is my concern, their health is their concern, and it's also none of my business." Said politely and without malice. It's just ingrained that deep.