While everyone has a sense of humor, what is considered socially acceptable is heavily dependent on culture. In some countries, it is acceptable to make quips and jokes about political or religious figures. However, in other countries, a negative comment may be considered a crime or blasphemy.
Dark humor is especially touchy. It is not everyone’s cup of tea and may come off as rude or offensive for some people. This does not necessarily mean that black humor is bad; however, use it with discretion.
Someone going through an illness like cancer may find that making fun of their condition makes it seem less serious.
There may be a point that these jokes can be a cause of distress or harassment (especially when taken too far). If your friend or family is going through a tough time, it would be best to avoid offensive jokes involving them and/or their condition unless they are open to it.
In addition, some people may mistake jokes about death, particularly suicide, as a cry for help. If you feel that death and suicide are on your mind frequently throughout the day, you may want to consider seeking out a mental health professional.
In summary, dark humor is a valid coping mechanism for many people. Making light of a heavy situation is a way to deal with stress and negative emotions. However, not everyone uses black comedy or appreciates it, so always be considerate of others around you.