Contrary to what many believe, Oriental dance (the correct name for belly dancing) did not originate as a dance of seduction done for men.
For centuries, the role of Oriental dance in Middle Eastern society has been that of a folk dance that people would do at joyous occasions such as weddings, the birth of a child, community festivals, and other events that bring people together to party.
Belly dance is natural to a woman's bone and muscle structure. The movements center on the torso rather than the legs and feet, as is common in Western dance. The belly dancer isolates parts of her body, to move each independently in a completely feminine interpretation of the music. The music seems to emanate from her body, as sometimes she emphasizes the rhythm, sometimes the melody of the song.
Today undoubtedly, there have probably been many individuals over the years who have used the dance in private as a tool for seduction.
So Dancers who writhe seductively on stage during their performances clearly either don't understand the cultural backdrop of the dance, or don't care. It's a social dance, created for families and friends to celebrate the joy of spending time together.
Btw many belly dancers now travel to the Middle East and North Africa to study the art form where it originated.