Either that, or their space robots could not protect them from the terr… oh, never mind. 
Well, the main reason the Empire’s military is so incompetent is that Darth keeps “remote-choking” the senior staff:
“You came out of hyperspace too early!” “GASP! CHOKE!” thud
“You let the Millenium Falcon get away!” “GASP! CHOKE!” thud
“You came back and didn’t bring pie!” “GASP! CHOKE!” thud
By the time of ROTJ, the shield station was being guarded by Admiral (recently promoted from Sergeant) Nosepicker J. Dumbass.
I heard there were a bunch of Assholes as well.
Just as a matter of principle, I’d have exterminated the Ewoks. I mean, I’m using the moon for my top secret weapons project, and there’s no real military or economic benefit to keeping the Ewoks alive. They’re not even humans…just stinking aliens.
Remember the Ewoks enjoyed eating humanoids. Probably the Empire kept them arround to deter visitors. They would have eaten the rebels if C3PO hadn’t been Gold.
THE EMPEROR: Then, young Skywalker…you will die.
zapzapzapzap
LUKE: Ow! Father! Ow!
DARTH VADER: (reaching a decision) My master, please go stand by the reactor shaft. So I can protect you.
Also, wasn’t pretty much the entire Empire being mentally micro-managed by the Emperor? Maybe that’s why the Endor battle was so pathetic, because Palpatine was so distracted by the fun of Luke vs. Vader that the ground troops were left to their own unsupervised stupidity.
Considering that the Empire felt that they had mounted their installation on the galactic equivalent of Disneyland, yeah. And remember, they had a shield generator that (normally) prevented anybody from getting on the planet. What did they have to worry about?
Remember, just about any and all of the Emperor’s (and, by extension, the Empire’s) shortcomings can easily be explained by simple arrogance. Palpatine thought that he saw all futures, arrogantly believing that nothing of significance would happen that he didn’t foresee. 'Course, he forgot the all-important rule… “Always in motion is the future.”
How? They had no idea where the Rebels WERE. Sure, I guess they could’ve just killed every single citizen under Imperial control, but it’s kinda daft to destroy your own resource base, isn’t it?
Ok, even if it was Disneyworld, I don’t think defenses consisting of a bit more than a few troops is out of line, but let’s assume that the defenses were ok. Why no airsupport once the shit hit the fan? The Death Star and Imperial fleet is overhead, after all. They couldn’t spare 5 fighters to drop in and help the grunts on the ground? No helicopteresque close air support? I’m just saying, for the shield generator that is guarding the Ultimate Weapon, one would have thought a little more attention would have been paid…
Heck, even Disneyland has that geeky pimple-faced minimum-wage-earner asking to see your ticket.
The Empire didn’t even put that much effort into defense.
As someone else mentioned, it’s safe to assume that war in the Empire would be very different from wars on 21st century Earth. Maybe there are issues that make “kill zones” a really bad idea. For example - and this is just off the cuff, so don’t be too hard on me if it sucks - maybe a large clearing would be too conspicuous from orbit, and too easy to target with orbital weapons. I mean, we can see cars very easily from orbit - a large clearing would probably be very easy for ships in the Star Wars universe to detect, and this would tell them exactly where the shield generator is.
Of course, the Rebels already knew. But if memory serves, this is the result of intelligence, not direct sensor readings. Perhaps if a hostile force just stumbled across the death star under construction, they might not be able to detect the ground-based generator in the normal course of things. I’m not a star wars expert, though - I leave it to those who are to say if my BSing has merit.
Unless you want to sterilize the planet with nuclear weapons (“I say we nuke it from orbit, it’s the only way to be sure.”), killing all the Ewoks is going to be a messy, messy business. I’d be all in favor of it myself - they’re too annoyingly cute for my tastes - but consider that without nukes, this is not something you can just do from the air without nukes - even Ewoks could probably dig bomb shelters. And you don’t want to use nukes, because then you take a perfectly good habitable moon and make it uninhabitable for a very look time. Even in a Galaxy-spanning empire with millions of worlds, and a demonstrated willingness to blow them up entirely if need be, that has to be a bad economic move. There are so many things you can get from a habitable world - food, water, shore leave, housing, the list goes on and on - that just nuking it seems like a bad policy decision. Princess Leia’s world (can’t remember the name) was a security risk, in the mind of the Empire. That’s not quite the case here, yet.
So, you can’t nuke all the Ewoks. Nor can you simply firebomb the forests - how long will you have a functional ecology, or even a breathable atmosphere, after that kind of holocaust? So you’re limited to air attacks - which will have limited effectiveness - and ground assault. As someone already mentioned, in a ground combat situation the Ewoks have the home turf advantage and vast numerical superiority - this would turn into the Empire’s Vietnam. And once they started. they couldn’t give up, because any operations on the ground - like running a shield generator - would face the threat of Ewok assault.
In short, a world war of extermination would be unwinnable unless the Empire used weapons that would make their victory pointless.
Also, given that the destruction of the Death Star probably resulted in the complete destruction of the Endor ecosystem (not to mention the probable extinction of the Ewoks) the Empire probably thought the Rebels would never try it. 
Well, I don’t know if you remember, but the shield generator was preventing a planetary bombardment. That’s why the used the walkers, because they just landed outside the shield(which I guess only protected the area around the base and not the entire planet) and attacked on the surface.
And notice despite being rather cumbersome, the rebels only managed to knock out two of them. If nothing else, they are worth it for the “Oh ****” value. Namely, you hear a far off pounding, you see little black dots on the horizen. You look at them through a telescope, see how big they are and go “Oh ****”.
Though wouldn’t such support ships be rather large and slow compared to the fighters, who could just evade them and continue down?
In X-wing(the computer game), before you can attack the death star surface, you have to take out a crtical satillite in orbit of the death stay. Near the satillite are a couple corvettes and a star destoryer, which aren’t anything to worry about unless you get close enough for them to shoot at you. The fighters they launch…on the other hand.
Come on, I’m not insulting you! Don’t you see it? I’m deffending you! Sorry, now I see you’re not a troll.
But the effects are disquietingly similar.
Btw (again), I don’t find this matter offending. I find it funny.
The above message was for Duderdude2, in response to:
Excuse me. Just to answer a question from Miller: Lines come from Ubik by Philip K. Dick.
And this is the last post I put in this thread, before someone tells me that I have nothing to contribute to SW. Unless I’m asked again, of course.
[sub]Coding fixed at poster’s request. But don’t all start asking for that, now. – Uke[/sub]
There’s a good reason why there was no kill zone in front of the shield generator bunker. Palpatine wanted the Rebels to get in. Remember, the whole thing was a trap from the beginning. And a mine field wouldn’t have done any good anyway, because as soon as the ewoks showed up, the battle quickly moved away from the bunker and into the woods, where the ewoks were able to go all Viet Cong on the stormtroopers. I still maintain that the whole ewok battle could have been salvaged in the Special Edition if Lucas had just added lots and lots of ewoks getting killed. Like, hundreds of them getting mowed down by blaster fire, with thousands more waiting to fill in the gaps.
BTW, Duderdude, having got some sleep, I should really apologize to you for flaming you outside the pit. As annoying as I find the eternal chorus of “Why do you even care?” in these sorts of threads, there was still no excuse for that.
Okay, all you kids behave yourselves now. I’ve got my eye on you.