Other than <PERSON>'s very valid points, several things would prevent this kind of naval strategy:
1) Usually there are patrols and other defense systems, especially near a capital. 2) Hyperfuel: As we learn in Solo: A Star Wars Story, hyperdrives need coaxium to fuel them. While it doesn't necessarily need to be refined, it is highly unstable when unrefined and also highly reactive, making it dangerous to use unrefined coaxium. Coaxium itself is expensive and the refining process also costs money. In order to move a full fleet, you need the coaxium to fuel them for the entire journey there, plus probably at least a partial return journey. The logistics of doing this for just a bombing run on a capital planet don't make sense. 3) Risk management: If you commit your entire fleet to an attack, but the enemy has sufficient strength to stop your fleet, you lose your fleet and the enemy gains the upper hand. 500
They don't even need to be stronger. In the Expanded Universe, <PERSON> and Tarkin are both noted to have used Star Destroyers (or similar cruisers) equipped with gravity cones, which generate a powerful gravity signature to pull ships out of hyperspace and prevent them from entering. They used these mainly for offensive maneuvers, allowing their exit from hyperspace to be more controlled, but they can also be used in hyperlanes to block access and establish checkpoints. If your fleet gets unexpectedly pulled out of hyperspace, the enemy has some time for free shots before your crews react. 4) Ethics (and some kind of related logical stuff): Most of the time in Star Wars, guerilla warfare is seen to be not targeting civilians, but military targets that will make an effect. A capital world, even if bombed to ashes, won't put an end to an enemy's military. As seen from the fall of the Empire, even a military group that suffers a loss of government will continue to fight as long as they have some sort of leadership. It's kind of hard to take out the entire chain of command of a military, so this wouldn't be effective as it would leave no government to negotiate a full surrender while leaving military leadership to continue the fight. 963