[Being hugged to death by someone who isn't used to being metal would be an extremely tragic way to go. Avoiding that is a good call.
Nathan doesn't know if the hug helps Kitty or how well she can even feel it, but it makes him feel better.. at least where she's concerned. He needs Kitty to be okay. This is important to him, and that's why he doesn't disagree with her even though he's relatively certain that many of the things that "it" could feasibly encompass are not going to be okay at all.]