George Lucas was/is, in a word: a visionary. He imagined a fantastic place where fantastic things happened. Then he engineered ways to put what he imagined on screen for us to see so that he could share it with us, and we will be forever grateful to him for that. That said, the original trilogy really is pretty bad-it's chock-full of inconsistencies and plot holes, all of which we are all quite aware of now and comfortable with and, frankly have come to find as part of the charm of the movies. When CGI finally became serviceable and George was able to go back and re-shape those movies into something more akin to what he had originally envisioned, he charged right in without thinking about the consequences. He could have waited until the technology was even better so that the CGI was smoother and looked better, at least. Of course, there are many, many changes we simply wish he had never made at all, but he maintained that it was "his story" and basically informed us that if we didn't like it, we could just go jump off of a cliff: he was changing 'em, anyway.
Then it came time to write the prequels and we were going to finally get to see the story of the great Anakin Skywalker and his downfall and transformation into Darth Vader. Only the Anakin we were shown was very difficult to imagine as ever being Darth Vader. And the CGI was used so gratuitously that it was very difficult for the viewer to make any kind of connection to anything he/she was watching on the screen. Too many CGI props and characters, all crowding the screen throughout each of the movies-the worst, of course being (ugh) Jar Jar. (And we thought the ewoks were bad?) I appreciate being introduced to new planets, new locales, new characters and new ships as much as the next guy (maybe more) but CGI is a tool to be used in movie-making. Movies are NOT showcases in which to display your ability to manipulate computer programs to develop convincing CGI backgrounds and characters.