If my understanding is correct, the means to traverse the worlds always existed for both the inhabitants of hell and heaven. I don't know that that would stop existing even if we did destroy this place.

... If I'm truly realistic, the odds are that this place will have to continue to operate in some capacity. However, if we can infiltrate and revolutionize it so that it is no longer hell in anything but name, perhaps there won't be any need to take that sort of risk.