I am not a Star Wars fan, either, inasmuch as I've only seen the movies once. However, I am a movie buff and an enormous D&D/RTS/General RPG nerd (I'm one of the people that was outraged when The Two Towers took a major and rather unscripted plot twist into Gondor). I've been taking notes and it's time for my term paper here.
As to the financial success of the movie:
First, the original Star Wars came out at a time in which the movie industry was not nearly so competitive. Less movies, more time to see them; admittedly, less interest. However, the stunning (for the time) special effects and general coolness, along with Lucas' brilliant marketing skills, spread word of the movie fairly quickly, making it a parallel to Harry Potter. It has nothing to do with the horrible dialogue and more to do with the cool fight scenes. Nerds, whether we'd like to admit it or not, really enjoy seeing those pretty little lightsabers whirled around and watching hi-tech spaceships get blown to bits. That's why the fad has grown to a cult-ish fervor.
Basically, as long as it looks pretty, it'll make good money. Day After Tomorrow? The Drunken Master movies (ok, the humor was pretty good, but the plot sucked)? Titanic? Charlie's Angels? I mean, come on.
Also, remember the movie doesn't have to cost a lot to be an enormous seller. Napoleon Dynamite had to be one of the lowest-budget movies of all time, but look at the sales on that one.
As to Lucas' directing job, I'm sorry, but I have to revisit it. Personally, I'd agree that he was making a political statement....but he missed the whole point. There's a number of angles you could take with this; anti-warfare, political drama, etc., etc. He also tried, N.B., TRIED, to make the movie bigger than it was, especially (this has been brought up several times) with the ridiculous love story in AotC and general statements of city life (the cantina scene in one of the prequels, I believe it was the first one). He's just one of those directors that, while I admire his works, wasn't particularly good at his job in the first three movies, which were the most enjoyable for me because of Han Solo's biting presence. The second series seem to be mediocre, at best (I saw tPM when I was ten and refused to watch AotC).
Don't mistake what I'm saying as that I don't like Star Wars. I'm too much of a sci-fi junkie to say otherwise. However, I'll repeat what many have already said; take that movie and find a co-director who can override Lucas' artistic vision. The movie could have been right up there with Casa Blanca, Vertigo, Gone With the Wind, and Citizen Kane.
Some random snippets I have replies to:
As to the relevence of a first draft:
A quote comes to mind. I think it was Hemingway that said, "The first draft of anything is always $H|T."
Someone mentioned a director's quote who said, "Like that, only better." I think that was the director of the Shining, which I recently re-watched....Peter something-or-another, I can't remember his last name either.
As to kid superheros, let me cite a few VERY successful series and individuals which are being soaked up by kids of all ages (depending, of course, on the target age)
Goosebumps
Teen Titans
Pokemon
Spykids
X-Men (my favorite character was always Rogue)
The "Swiftly Tilting Planet" series
Matilda
Little Women
The Redwall series (yes, I know it features mice, but the principle is exactly the same)
The Chronicles of Narnia
The Legends of Zelda
Blue's Clues (Joe)
Hilary Duff, Lil Bow Wow, JoJo, and Lindsey Lohan
Harry Potter
The Incredibles
Those are just off the top of my head, I read a lot more than I did anything else as a kid. My point is, kids look up to older kids, not adults, and most of them are looking for confirmation, IMO, that the underdog really can save the day (I know I'm playing armchair psychologist, but stick with me here). For most children, anyone over the age of 25 is a "bad guy" until they reach the age of, let's say, 16 at the earliest, 19 at the latest.
Anyways, those are my rants. Do not attack me as being incompetent because I haven't seen the movies fifteen billion times, as I will ignore those accusations, but feel free to critique/discuss any other part of the post.
Oh yes, and for all those who completely debunk Lucas, rather than ask that he improve upon his methods: go watch Plan 9 from Outer Space and come back and tell me how they compare. He's not quite the worst out there.