If anything, this makes it makes it possibly more walbangerish.
Let's assume for a moment that you don't want to just nuke/bomb/kinetic strike a planet into oblivion, because you for some particular reason actually want to land on it.
Now lets assume you maintain utter "space superiority" around the planet. (Presumably this is the purpose of complexe capturing.) Spreading ship patrols all over close-orbit of the planet isn't an option; a planet's far to large to do that without expending hideous amounts of resources. Considering the engagement range EVE starship battles seem to take in, covering the entire planet in anything (even drones or automated turrets) would be an excersize in grandoise, self-sabotaging futility. What that leaves us with is the option of deploying long range-probes across the planet, constantly watching them for any results, and scrambling warships to intercept any craft that approach the planet. Another variation on this would be to analyze the planet's terrain to discover good landing approaches, then more densely cover these areas in ship patrols. Even with these approaches, the prevalence of cloaking technology in EVE along with the adaptability of the warp drive means that hostile blockade runners or other small, fast ships could warp into low orbit, deploy orbitally dropped resupply pods (along with a suitable number of decoys and E-warfare pods to confuse any surface-to-air defenses) and then floor it out of there in a matter of seconds - in all likelyhood before your patrols could nail them down.
Now that we've (only moderately effectively) blockaded a planet, lets look at what we have to do still - landing, suppression of local military, and organization of our own government systems.
1 - Landing - frankly the easiest part. PF indicates "limited" orbital strikes exist which, while crippling to ground installations, wouldn't utterly ruin the planets biosphere. So, anything that fires on your transports during their descent is likely to find itself very quickly the target of some unwelcome attention. This will discourage anything but remotely-launched, disposable systems; systems which are also likely to be more succeptible to E-warfare (which is, by the way, the only thing your transports are going to have in your favor). Even so, shooting down a single transport could cause hundreds, if not thousands of casualties.
2- Suppression of local military - This is where things get tricky. I won't go down a list of all the times a smaller, less-well-equipped force with greater motivation, a knowledge of the locality, support of the local population, and lots of space to retreat into has utterly decimated a larger attacking force, but I will give a one choice example to illustrate my point: Iwo Jima.
During the battle for Iwo Jima, a vastly undergunned, far smaller force with knowledge of the terrain and excellent preparation inflicted horrifying casualties on a much larger force. In my opinion, this would be the best option for fending off (or at least delaying) an orbital invasion - wait until the first waves have landed, the initiate an attack from concealed positions while using the terrain to remain unseen by the heavy weapons of the orbital fleet. Continue to fall back, inflicting casualties as you do, and then commence an assymmetric war to counter the enemies' ever-increasing numerical advantage. In this way, a far-superior invading force could be bled out which, while not stopping them, would make invading the next few planets a... questionable excersize.
3 - Setting up you own goverment - this might be the easiest, or the hardest step. How resitant is the local populace? How much freedom are you willing to afford the local population? How ruthless are you willing to be? A great deal in terms of need for continued occupation hinges on these questions. It might be a smooth transfer, or a subjugated but not accepting people, or even a planet-wide insurgency of sabotage and ambush - again, how ruthless are you willing to be?
TL;DR - Invading a planet is a truly incredible expense of resources, including lives. Done right, defenders can inflict terrifying casualties on attackers while being resupplied indefinitely by speedy orbital transport. Even after the official military is crushed, you've got the potential of an uncooperative population and/or insurgency to deal with. So, if you spend all this invading one planet... how many can you sustain? The idea of the Empires fighting over entire planets time and time again starts to rapidly become diffiult to accept.
DISCLAIMER: The situation I've outlined here is a "worst case scenario" for the invaders. NOT ALL INVASIONS will follow this outline. Many may be bloodless, or end in the quick suppression of hostile elements. This outline is meant to represent the reasons why repeated planetary invasions would NOT work, not the reasons they would - those, I feel, are already self-evident.