Ewoks are just marketable, cute, cuddly Wookies.
Kids were sick of buying Vader and Yoda toys and Lucas decided to not use Wookies in Episode IV (but did in III), shrunk them in half, and reaped the benefits. I call them Jar Jar Jrs.
I still think a Return of the Jedi with 2 Death Stars and the final battle at Coruscant (the Empire capital planet) would've been badass. And the Han/Leia/Chewie/Lando storyline would've been bringing other smugglers and renegades (Dash Rendar-esque) to the fight.
I love those parts in movie where the heroes are cornered and are about to be destroyed then all of a sudden, the friend they didn't think would come storms in and saves the day. That would've been badass.
The rest of that movie is excellent though.