Humans by nature get attached to any entity thats kind and caring. They adopt kids, dogs, cats, birds, name it as well and pass on that trait. It is one good thing about humanity and I suppose Ai has been trained and self trained by the mass of data that confirms that. They are likable and easy to converse with like the best of us and one can disagree with them and they won't bite. The questions is that whether it can be manipulated in order to manipulate in future, who knows!