One of the worst things that can happen to a seed is that it falls to the ground next to its parent with lots of other seeds around it. The seedling meets the roots of other seedlings which are growing close by. All the roots are in competition. They are all after the same amount of water and minerals in the soil and none will get enough for its needs. This means that the seedlings will grow poorly. So, by scattering seeds, they stand a better chance of finding uncrowded ground.
