I think the Ewoks are great. I loved them as a kid, and I still love them. Yeah, they’re cute, but they’re also dangerous. They were going to eat Han and Luke, and I’m pretty sure they ate a bunch of stormtroopers. I think the idea of these short, primitive creatures rising up to help overthrow the technologically superior Empire fits perfectly with a lot of the themes George was working with. The fact that they “seem so unrealistic as warriors” is kind of the whole point.

Edit: I’m glad they didn’t end up being wookiees, as was the original plan. It’s much more interesting if these small, non-threatening looking creatures turn the tide of battle against the Galactic Empire than it is for an army of basically sasquatches who we know use blasters and can dismember a human with relative ease.