There is a gap, and if there wasn't I wouldn't be a regular at a website that specializes in fan edits. However, the gap is ridiculously overblown by fanboys in comparison to what it actually is. My parents view all 6 movies as being similarly cheesy and the only real thing they complain about in the prequels over the OT is that they can't stand Jar Jar's baby talk. With fanboys though, the movies also had to pass through the additional scrutiny of not having 20+ years of nostalgia to back them up. It's not that I believe that the prequels are better than they actually are, I just accept that the original trilogy is not as grand as my nostalgic feelings for it would incline me to think.
If the prequels were as bad as people make them out to be then they wouldn't be nearly as popular. They segmented the fanbase into those who accept them and those who do not, but to most people outside of our fandom, their attitude towards all six movies is "it's Star Wars."
Also, before you jump in and say "people will buy anything with Star Wars on it," I'll point to the theatrically run Clone Wars pilot which only grossed 68 million dollars. Yeah, that's still no chump change (especially considering it barely cost them anything to release), but compared to the other Star Wars films it's pretty unimpressive that it couldn't break 100 million. People will watch what tickles their fancy, and in the case of the prequel trilogy a great many people liked them enough to push them to the top of the box office and DVD charts. Clearly, general opinion of the movies is not nearly as negative as one might think if just looking at some of the comments of the fans (and even in the fanbase the margins aren't nearly as negetive, because complainers are always the loudest).
Something I've noticed in talking with my non-geeky friends is that they find Star Wars fans to be quite amusing. Some even go so far as equating the malevolance of fans towards George Lucas as being like if Christians were constantly angry at Jesus, which to us might sound absurd, but that's because we're not on the outside looking in. To the non-fan, Star Wars fanboys are an argumentive lot who are impossible to fully please, and when we're not bickering with each other we're biting the hand that feeds us.