If science fiction is about how scientific advancements impact humanity, then Star Wars can’t be sci-fi. There aren’t any real humans. It’s just a bunch of aliens… with many that happen to look like humans and happen to speak english. It’s a long time ago in a galaxy far far away, so it’s got nothing to do with us.
Now, if they went the Battlestar Galactica route and said that these were our forefathers who would one day colonize earth, then I would argree that it’s sci-fi.
Not that I really care. Star Wars just belongs in the genre of Awesome.