appeals to all ages on different levels
While younger children may not understand the mysteries, they'll love the action. Some younger children may initially be scared, but those fears will quickly dissipate since they'll see that the villains are fake, thereby teaching children that ghosts, monsters, etc., don't exist. Older children (and adults) will like and appreciate the mystery. Teamwork and persistence are valued and encouraged. The only problem is the mild sexism with the way Daphne is portrayed. But again Velma makes up for that. We must also remember that the portrayal of Daphne is a reflection of when this series was made (1969-1971). This problem with Daphne's portrayal got corrected in the 1980s. From that point onward she was less trouble-prone, more assertive and more able to make decisions for herself.