I admire and think George Lucas is awesome. My feelings about the prequels have always been mixed. So much was right about the films. The design aesthetic, the music, the podrace, the film titles, the opening crawls (IMO,...I know that most people didn't like them), Ben Burtt's sound effects. On the other hand, there were vital things that were wrong, which made them bad films by any metric by which you'd normally judge narrative and acting. Despite all three episodes having things that made me cringe (mostly the acting and writing), I still defended the prequels fiercely to others until I saw Episode III. These films needed to be judged as a trilogy, and I still think they do, to an extent. However, following Episode III, I couldn't deny that the quality was different from the Original Trilogy and that the x-factor which determined their problems seemed to be George. These were bad movies, but they were bad movies which I liked. And I liked them, in part, because, as the DVDs were released, I tried to crawl into Lucas's likely high-functioning Aspie brain and figure out what the hell he was thinking. And when I emerged on the other side, to me, they were still Star Wars.
I really have hated the rift which has existed among Star Wars fans since 1999. It seems that you fall into one of two camps: prequel-gusher or prequel-basher. Very few have found the space in between. To give you examples of what I find fallacious about either position, I would point to two popular analyses of the prequels. In the prequel-gusher camp, I think that Star Wars Ring Theory tries too hard to find genius which, in all likelihood, just isn't objectively there. On the other side, you have Red Letter Media's Mr. Plinkett Prequel Reviews which, while very entertaining, miss just as much of what's good about the prequels.
I think that, if you're going to find any genius in the Star Wars prequels, then you have to start with where George Lucas was in his life when he made them. He was a middle-aged divorcee raising three kids, all of whom I believe he adopted. I would argue that the prequels, especially the Skywalker story arc, is a love letter to his kids, especially his son Jett. Surely Jett is the only reason that George made the otherwise baffling decision to make Anakin Skywalker a 9-year-old born into desperately disadvantageous circumstances.
With the prequels, George Lucas basically made the entire Star Wars saga into a 6-episode series with the overarching theme of "The sins of the father do not have to be the sins of the son." The core series stayed such for ten years. Despite their serious flaws, many story points in the prequels were communicated subtextually and are lost on most because they refuse to see past the serious flaws which the movies have. I'm sure most of us appreciate the use of visual and circumstantial parallels which place Anakin and Luke in similar situations in which they are given similar choices but ultimately end up in different places.
I think we would have gotten different films altogether if George had made them at any different point in life. Who's to say if they would have been better, though? He obviously had a lot of directorial "rust," having not directed a filim in 20-plus years by the time of Menace, and I think that is to blame for much of the phenomenon of great actors giving the worst performances of their careers. With regards to dialogue, writing that was even George's weakest area at the time of the original films. And while I think that some of his prequel collaborators bear a little blame for not giving him more feedback (I have only guesses as to why), the buck ultimately stopped with George.
With Episode VII, I think Mr. Abrams and Mr. Kasdan and Ms. Kennedy are trying to heal the rift among the fans. They want us in the theater in order to reaffirm to us that Star Wars can rise to the level of what most people have always said were its best moments. I seriously question the perceived prequel hate from J.J. Abrams in the marketing. I really think that George's "btfo" comments are part of the marketing, too: maybe not a year ago, but at least they are by now. I think that Episode VII will be scarce as far as prequel references go. But I hope that early Episode VIII and IX rumors which I've heard, which indicate that there will be more explicit prequel references to tie the trilogies together, are true. Think about it: they really have to, if the saga is to maintain any semblance of thematic symmetry.
The only other option is to remake the prequels. And I will admit that, with as prone to reboot franchises as Hollywood has been the past ten years, the idea thrilled a part of me at first. And, then, I thought about it: George Lucas is getting pretty old. He is loaded with money and has access to good healthcare, but I know he's a diabetic with weight control issues. This is the man who I think we will find out in less than two weeks basically gave (for $4 billion dollars) the franchise back to the subset of fans who claimed he never had any stake in it since 1997. I sincerely hope that Disney and Lucasfilm never insult him in the worst way imaginable, at least not while he's still with us.
tl;dr: Cut George Lucas some slack. He deserves praise, he deserves criticism. It's not all-or-nothing. I think the new filmmakers will heal the rift among fans as much as they can.