My reactions to Gregor surprised me, for the creature he has become, 'monstrous vermin', and the habits he develops as his condition deteriorates, eating rotting food and leaving sticky messes, is one most likely to cause revulsion. Instead, he elicits most positive emotions. In particular, he arouses feelings of pity, compassion and sympathy for his plight, while his family tend to make me feel disgusted with them and their treatment of this changed Gregor. Only his mother continues to want to protect him, even after seeing him as 'an enormous brown patch against the flowers on the wallpaper.'
In asking myself why I should feel this way, I am led to look deeply at my own beliefs and values. I begin to liken Gregor's plight to someone having a mental breakdown, a stroke, or being terminally ill, or suffering dreadful disfigurement. If this happened to me or someone I cared about, coping would be hard but I would hope that kindness and concern would be given to the 'changed' me, and that people would remember that the real person is still in there somewhere.
Although Grete does initially look after her brother, it is she who wants to kill him, telling her father, 'It's got to go....you've got to get rid of the idea that that's Gregor'.