I'm not a big fan of the prequels, but I am not quick to dismiss them either. I think the main reason why people have their panties in a bunch is that they don't seem to factor in how all of the parts add up to a whole. The prequels themselves were kind of an experiment for Lucas. He had to take a set of movies that were established well beyond his original intention for them, and weave all of it together to create a back story. I could imagine that if you are working off of an original outline that you wrote 30 years ago it would be difficult to flesh it out. If you add to this the fact that Lucas already had it in his head that people were not going to like it as much as the middle 3 episodes, which is why he started there, you can see why this project wasn't going to feel the same as the beloved trilogy from the 70s and 80s.
Prior to the productions of episodes 1-3 the back story was something that you had to find sifting the countless pieces of merchandise (books, trading cards, comics, etc.). Eventually fans would pull these random bits of info together in order to explain the glaring questions that less fanatical movie goers would have about episodes 4-6. In a way you can see this as an oral tradition that had begun amongst Star Wars fans. They knew how the pieces added up to their favorite elements and had those scenes well in mind. When Lucas put the pieces that he planned on using in a movie there was outrage. It didn't fit in with how the fans had envisioned these elements.
The story of episodes 1-3 plays out in the same way the earliest mythologies work. There are very few reasons that are given as to why two characters fall in love, they just do. Sadness is felt by Obi-wan toward Anikan, because he's his master and his student went against the way of his teachings. Anikan falls to the darkside , because he's afraid of losing his love. The emotional elements of the main plot are base. What ties this trilogy with the original are the subtleties of these major events, and no I don't mean the rehashing of one liners. When one views these movies in order one can see a subtle dynamic in the previous generations actions that shape your perspective of the original trilogy differently. I believe that was what Lucas was going for with the prequels. He was well aware that lightening never strikes the same place twice.