Balancing on one’s head is an act commonly done to show off, much like when people do hand stands. Regardless it is quite flashy, and some people use the head for extra stability when they cannot do a full hand stand. One such move is done in yoga where the head can act as extra support.
Wrestlers and other athletes in combat sports regularly train their necks. This is because the neck is a vulnerable spot that houses the trachea and also the spinal cord. Damage to this can cause permanent paralysis, which is a fate worse than death. As such, extreme care should be taken when doing things that places large amounts of strain on the neck.