Back in the 60's people didn't think smoking had any negative effects. We didn't know that it was harmful so many people in society smoked, and because many did it, society thought it was ok to do. However now, as mentioned in the previous answer, scientists have found that smoking causes heart and lung disease, including cancer. After this was found out, less people smoked. Because less people do it now, society frowns on it, and thinks it is negative and harmful, and sometimes even rude.