Because that is the Cat's "Role". All of us are monsters. Miserable, Misshapen creatures. Don't tell me you think we're happy like this? That we enjoy being freaks? Do you know how many handicaps we have, how much pain we go through, just to survive within the framework of this world...? Do you? To us, the existence of the Cat is our salvation. Without him, our lives would be completely unbearable. You see-that monster is the ugliest of us all. He's inferior to us all. So it's only natural for him to be discriminated against, disrespected, and locked up. The rest of us look at the way he's treated-and we signed with relief. "Thank God," We think. "At least I'm better off than that." You should ask the others sometimes. "Did you know he was going to be confined? Deep down, don't you feel superior to him?" They won't know what to say. The Cat was prepared as an outcast creature...for our sakes. And Kyo...knows that too-.

― Shigure Sohma Tweet