Some bias surely exists with the prequels, but it leans harder in the opposite direction, IMO. In reality, they should have faded away into obscurity like other irredeemably bad movies such as the ones that Uwe Boll makes, but because it's Star Wars, you'll find a few apologists still defending it.
But if you can argue that these are good movies, then you can argue that just about any movie is good if you lower your standards enough. Like "Hey, crappy romantic comedies don't ENTIRELY make me want to blow my brains out-- That's something, right?"