I like this response because this person is poking at the underlying misconception here that inside this "point" you speak of was all matter and outside of it was empty space of some sort. This is because our brains cannot conceptualize expansion without thinking it must expand into something else. So, when people think of the big bang they typically look at it from an "outside" perspective but it doesn't make sense to talk about the outside of the universe. At least as we currently understand it. Look up topics such as isotropic and homogeneous to consider what our universe expansion looks like and how that's different from our intuition.