Because they are a travesty to what Lucas originally created. The prequeles created more loopholes and inconsistencies, it's like Lucas forgot what the originals were about. I will list a few of my own pet peeves about the prequels: Jar-Jar Binks, enough said. Midichlorians... ***? Hayden Christiansen (or whatever his name is) as Anakin. Could they have picked a whinier, more annoying actor to play what is supposed to be a very likeable character until his "seduction" to the dark side? Far to much focus on a love story that was neither romantic nor interesting. We all knew that Anakin and Padme fall in love and have kids, we didn't need the bulk of a movie to show us this. Not nearly enough Jedi BMF scenes showing how powerful Anakin really was. Too much fluff and filler, not enough actual Jedi stories. Watch The Clone Wars animated series, these are the kinds of stories that should have been in Clone Wars the movie, not an uniteresting love story that was poorly written and acted. The final end EMO "NOOOOOOOOO" from Vader in Revenge of the Sith is just, well, lame. Not nearly enough Vader in the last movie, should have seen far more of him. To much wasted time on the "seduction" to the darkside which amounted to little more then a deceptive trick on Palpatines part. I could go on with more loopholes, but I think you get the idea.