I didn't consider dimension collapsing bombs realistic either. It is the objects sped up to a fraction of light speed which were more scary. The cylons carpet bombed the planet with nuclear bombs which was plausible.
Nuclear carpet bombing is only sensible for short-range attacks. On longer ranges, fast projectiles are the way to go, because you need to accelerate your weapon anyways. And by just putting all the energy and resources into acceleration, you do recycle the motion energy as destructive energy.