also rebs can sneak attack a planet and get on the ground, bypassing your fleet.
also, some planets are so well guarded that you may not be able to take it without great loss. Ever try to assult a well garrason planet with only 3 open assult slots? not pretty. easier to just blow the place up then to loose lots of units .
Master TKA | Master Medic | Doctor
I dub thee the Emperor's right foot. Now go out there and Kick some Rebel butt.