@Furgar Cinderella certainly wanted the marriage too, with the last scene showing her wanting to prove she was the owner of the glass slipper (thus being able to marry the prince).

Ariel was absolutely interested in marriage with Eric too, since she stayed a human to be with him.

Belle reads stories about Prince Charming, and came back to the Beast and declared that she loved him.

Harpies just cannot stand that women just might also like the idea of marriage, so they create these narratives.