Did Star Wars #1 & 2 suck? No, but there was no way that they could have the impact of the original movie. When Star Wars (I'm not going to call it "A New Hope") came out, movie makers had forgotten how to make adventure films and had never figured out how to make a science fiction adventure film. It was the perfect convergence of new special effects technology and old-fashioned story telling.
By now, almost 30 years later, movie makers have it figured out. There are so many good adventure movies coming out that they have to make back half their investment on opening weekend since the next good one will be out in a week. Really great adventure movies come out every year or two. Audiences have seen two installments of the Lord of the Rings come out since Attack of the Clones was released. The only competition for the original three movies was Indiana Jones.
Keeping that in mind, the two new movies could not have made the impact that the originals made, not with so much competition going on.
Lucas did stray in creating his characters. The original characters were very identifiable to a 1970s audience. Luke was a farm boy who liked joy-riding. His idea of a good time was shooting over-sized groundhogs from an airplane (T-16 Skyhopper). Han was based on moonshine smugglers driving around back roads in souped-up stack cars. This was a whole genre of movies.
Leia was an exception. The feminist movement objected to the traditional heroine as someone who needed rescuing and moviemakers were having trouble figuring out how to handle women. Lucas solved this by inventing a spunky princess who took over her own rescue.
The plot was nothing spectacular. Most science fiction written in the 1960s and 1970s had the same premise of a farm boy suddenly going out into the world and saving the day.
Lucas continued to lift elements from popular culture. In Empire Strikes Back, Luke doesn't realize at first that the little green guy is Yoda. When we see Luke training with Yoda, he is taught to draw strength from the Force and to levitate things. We never see him practice with his lightsabre but he can now hold his own against Vader. This came from the Japanese and Japanese-inspired literature of the time. A samurai in training is given menial tasks, learning important lessons without realizing it. He never actually practices with his sword.
Skip forward a couple of decades. The Phantom Menace had evolutionary rather than revolutionary effects. It looked good but the Matrix won the effects Oscar. The Lord of the Rings proved that Weta could do anything ILM could do and make it look as good.
The storyline was more abstract, also. Evil was a trade guild with the real villain hidden. Attack of the Clones was similar - the story arc traces the rise of the Emperor but it is subtle. We know who the bad guy is but no one else does.
Also, the characters are more remote. It is easy to relate to a farm boy. It is much harder to relate to a Jedi apprentice or a slave.
None of this means that the newer movies are worse than the originals, just that they cannot have the impact.