One idea is that the voids in the universe are more or less uniformly spread out in the universe, and of about the same physical size, so that along any line of sight, you intersect clusters of galaxies on the boundaries of these voids, and this leads to 'quantization'. But there is no reason why this should be a property of space itself. Some astronomers even doubt the effect is real given the very limited and selective data we have so far on the distribution of galaxies. We have only 'mapped' less than 1 percent of the volume of our observable universe afterall!