A giantess can really scare people. Once they see her, they start running away in fear. They realize that they have to save their lives and that this is their only chance.
Giantesses are always considered as a huge danger. And maybe this is right. Only few of them are kind and gentle. Most of them just feel the desire to crush and eat living people. It gives them pleasure and satisfaction.
Credit to Giantess-7of9