Going back to the original posting...for me, it was basically that TPM was such a failure to meet expectations and anticipations that it soured the taste of the other 2 for many people.
I remember as a boy when Jedi (or I guess I have to call it RotJ now) came out, or I think even during empire, there were rumors of a prequel AND sequel trilogies being planned. We longed for that faraway year 2000 when they would come out.
So that when after a decade and a half of speculation and "meditation" on the Star Wars galaxy... we got some major disappointments. Obi Wan had said Anakin was a great pilot when he first met him... but he was a slave boy (emphasis on boy), so that threw it off. Jar Jar Binks did not bring the funny like C3PO & R2-D2...and C3PO;s origin seemed contrived.
Also, the acting of Young Anakin, and Hayden Christensen as older Anakin were a problem...and since he's the lead, that's also leaving a sour taste. To me, Samuel L Jackson was just kinda there, but no one seems to complain about it.
Other details that were annoying..for me, was that the Clone Wars were kind of one sided, in that it wasn't Clone vs. Clone, but just that one Army had them (and they were the "good guys" of the war)
I actually liked Revenge of the Jedi and consider the opening scene the most epic opening of the Star Wars films. Had the rest of the films been like that, we wouldn't be complaining about them today.
Also, some of the other acting, particularly that of Ewan McGregor as a perfect young Obi Wan, and Ian McDermid as the Emperor, was really good.
Contrast that to The FOrce Awakens, which DID seem to match the hype & anticipation. Part of it was the advantage of being new, so not bound by something previously set up.
I mean, if go back and watch it (haven't yet), then I am sure the flaws will pop up...but the feeling of getting ready to watch it , and doing so, was a good feeling,