Weaker characters can sense people from interstellar distances (like Cell Saga Goku sensing New Namek from Earth, not to mention other areas of the universe), so I don’t see why Buu would be targeting stars. And it doesn’t make much sense from what we’ve seen.
Plus, wouldn’t the Supreme Kai say he’s been blowing up stars? The Supreme Kai doesn’t even go onto clarify that when Vegeta says (thinks, technically) Saiyans can do what Buu did, he just says Buu’s well above Frieza. From a narrative perspective, busting Solar Systems would make him seem like a huge threat.
My point was more that his blast doesn’t destroy anything except Earth, but that’s kind of stupid now that I think about it.
Edit: I’m a little tired. Are you claiming he’s not just destroying planets with life? If so, I guess I can get behind that.