We should stop telling scary stories because they can cause unnecessary fear and anxiety, especially to those who are easily frightened, like young children or people with a sensitive disposition.
Scary stories might seem fun for some, but they can have a negative impact. They can lead to bad dreams and sleep disturbances. Also, in a group setting, it could make some people feel uncomfortable and excluded if they don't enjoy that kind of thing. So, it's a good idea to stop telling them.