A spaceship is tiny when compared to a planet and they're vastly more maneuverable than a planet side installation.
Consider the mass differences:
Space Shuttle: 74 tons dry and small enough for three to be displayed on an NFL football field with room to spare.
Earth: 6.585 billion trillion short tons.
Something the size of the Space Shuttle can avoid getting hit by practically everything unguided headed its way at starship battle ranges. Something on a planet the size of Earth can not.
If you have an effective orbit to surface weapon on something the size of a space shuttle you don't need to hit a planet because you're trying to hit weapons small enough to use the SCUD paradigm. You need to hit something the size of a space shuttle. In fact you need to hit all of the somethings the size of a space shuttle which can be buried or submersible or disguised as mundane buildings or fishing trawlers. The seagoing ones can dodge and unlike the attacking spaceships they don't have to expend propellant to do so. Can you hit millions of hidden and or submerged targets faster than your evasive maneuvers run you out of propellant? If you can on something the size of a space shuttle your propulsion tech is so good that you can make planet crackers so easily that if you don't also have planetary shields that make orbital bombardment an exercise in futility you either have a demilitarized MAD fearing galaxy or you don't have intact habitable planets. Unless you're writing about a civilization that just discovered them and is demonstrating the "poison pill technology" solution to the Fermi Paradox.
Also, starship battle ranges are by definition the range at which they can be hit.