Kirby is cute because he represents the purest form of childhood innocence in days of war and violence. Despite we as society are worse today than we were in the nineties, the decade of Kirby's debut still had fear and famine, and his cuteness gave gamers hope. But it's not just his physical appearance that is cute, playing a Kirby game or seeing gameplay footage of that grants a sensation that is adorable. He is an unorthodox warrior, borrowing abilities from others, but the way he executes it is so pure, so fresh, therefore it can be cute. It is a spiritual connection with the gamer and the spherical figure.
I can´t tell why he is cute. He is just cute. I think it is he´s smile. I just love that smile. I have never seen more sweet smile. It can too be he´s laugh. It´s sooooo sweet. After all i think hes one of the sweetest characters in the world.