I first saw TPM some ten days after the Croatian première (which was almost five months after the domestic release, that kind of shit was normal back in the nineties), and I don't remember a single person leaving the (completely packed) theatre bitching about the movie. In fact, a lot of people appeared totally psyched (mostly because of the visuals, I reckon). Also, out of the dozens of my friends and schoolmates who saw it (it was considered a "must see", much like Avatar a decade later), not one of them talked trash about it.
You raise an excellent point. When TPM was first released, it seemed as if everyone loved it. It wasn't until about 3-4 months later that the honeymoon period was over when opinion turned.
Eh? I saw the stupid thing during the first week. When the lights came up, I looked at the people I was with and we all sorta shrugged...well, that kind of sucked, didn't it? It sure wasn't what we were expecting. None of us needed a movie critic to know when a movie doesn't deliver.
By the time AOTC came along, we weren't expecting anything but garbage. Even then, I was quasi hopeful, since Anakin was now played by a different actor. Maybe the problem was that they never should have focused on him as a kid? But then Hayden did that freaky creepy stalker thing of his (maybe he doesn't realize he's doing it? but that's what a DIRECTOR is for!) and I knew it was all over...