I remember someone (I think Orang Utan) saying that complaining about Phantom Menace was like moaning that Police Academy 7 was shit. I (still) beg to differ. The original Star Wars films, whilst not exactly Shakespearian, were iconic, and had a certain charisma and chemistry about them. Phantom Menace was almost entirely lacking in anything like that.
I don't mind something being mindless. To me a bit of mindless art is just as worthwhile as a bit of 'high' art when it's done well: Raiders of the Lost Ark, Star Wars originals, Die Hard.
And I don't mind something being for kids: I love Toy Story, the Incredibles, even cheesy 80s films like Flight of the Navigator.
The Phantom Menace, though, managed the amazing feat of being both mindless and boring. They had this cool villain, Darth Maul, yet we hardly saw him at all. Half the film was taken up by people talking about tax blockades. The pod race took way too much of the film. Jar Jar Binks was just annoying, rather than funny.
Compare that with the original star wars film - the Cantina scene, Han Solo, Chewbacca, the Death Star destruction sequence - you can see that Phantom Menace was simply shit by comparison, it's not a matter of one always being crap in teh first place.