The Ewoks are an early example of the awkward racial profiling by proxy we would get in the prequels.
George’s main talent is evoking nostalgia.
When his early successful films came out cinema was rather bleak and forward looking to a post nuclear wilderness run by apes and/or mutants the only surviving humans were on the moon which was escaping the solar system at super-luminal speed. All authority figures were as corrupt as Nixon and all children were possessed by or born of the Devil.
A film like THX-1138 fits into that sort of world with ease, maybe too much ease so he then made his first hit which practically invented the 50s nostalgia wave of the 70s, and the Star Wars and Raiders with their nods to cinema from happier more deluded times.
The problem being that those serials he was trying to evoke depicted some pretty awful racial stereotypes. The cowardly ‘Jap’, the noble savage, the money obsessed hooked nose Jew, the lazy black, the cannibal native.
The Tusken may fill the role of the Native American in a Western but he has the virtue of not having any of the physical tropes (no feathers, no war paint, no war song, no throwing axes, he gets a wigwam in the prequels but more of that later) so they work.
The Ewoks are beginning to be a bit too close to the hero eating natives of Tarzan to be comfortable. There is a serious debate going on now about the problems perceived by Slave Girl Leia and fat sultan Jabba but the Ewoks are more of a indicator of things to come for me than that.
In the PT we have the robot loving sneak attack slit-eyed Trade Federation, the money obsessed hooked nosed trader and Stepin Fetchit.
I don’t think George is trying to be offensive, his friends and family would hopefully not hang around such a man who would but I think he just doesn’t think like other people do and he increasingly distanced himself from people who might have steered him into more sophisticated ways of doing what he wanted. My main bag with the Ewoks is they are not seen as culture that could take down Imperial troops before the battle. Their look would be fine if it truly was subverted by showing the Imperials already being their victims. 
That way the overnight traps make sense. The time for trophy helmets would be before the battle not after it. That way Han’s dismissal of them as cute Teddy Bears gets inverted, if we get a taste of foreknowledge that they could handle themselves and reclaim their forest without the outsiders help but not with the ticking bomb of the metal moon that needs to be destroyed. The Bolas gag gets used in both ROTJ and TPM which marks it out as the precursor of awfulness to come.
