Because it tries to fill it, so it cease to exist.
silly brabennite.
Nature tries to join the Void. It does this by trying to get closer to it. by getting closer to the Void, it becomes more and more balanced because the Void is absolute balance. Wherever there is something closer to the Void, nature will try to get there. Until eventually it can succeed and finally reach it. Achieving it's long awaited ultimate goal of ending it's journey of imperfection.