The difference between the Star Wars Trilogy and Indiana Jones Trilogy of the 80's and the new movies are that fans have been waiting for this movie for years and years. Yes, looking back on it, Star Wars Ep. I really wasn't that great. But people had been waiting for that film forever, and by the time it was actually close to coming out, people were in a frenzy for it. I think that even if Ep. I had been on par with ESB, I think people would of been dissapointed, because after all these years and all the talk about it, everyone's expectations were sky-high, and unrealistic. Its similar to comic book movies, where fanboys gripe that their favorite villian, minor character, or scenario didn't make the film, and so it sucked.

I can see the same thing happening with Indiana Jones. I don't think its a "blame it on the fans if it sucks", but just a "go into the film with realistic expectations"