The whole 'Post-Vietnam' argument about Star Wars in the documentary is another attempt by Lucas to re-write history.
Star Wars was beloved by everyone in 1977, and big part of that audeince was people like myself (young kids). We weren't old enough to understand the ramifications of the Vietnam War, so the thought never crossed our minds. Star Wars succeeded in 1977 because it was a great movie, it appealed to everyone, and had ground-breaking special effects.
And people forget that Rocky came out in 1976, where he was a Luke Skywalker-like hero that fans could get behind and love in the movie.
I would ask all new fans of SW to ignore all of Lucas's propaganda documentaries. Just remember he said in 2005, "There are no more SW movies, as the story is about the Tragedy of Darth Vader, and the movies are meant to be watched 1-6"
And now we have the Sequel Trilogy 8 years later.....