Yours is the most accurate critique. Jackson attempted a completely different way of telling the story and it failed utterly. How was the audience supposed to perceive the films? I mean, how could we have found them anything but boring?
Perhaps the biggest failing of the films was not making us care. Most of the dwarves were rubbish and this is possibly due to Jackson's energy being elsewhere. But every director should know that you cannot make an audience care about more than 3-4 characters. That's basically Gandalf, Thorin and Bilbo... and we already liked Gandalf.
Now Bilbo didn't like Thorin and that's a problem if you're telling the story from his perspective. If the rest of the film had been good enough, Jackson would have got away with it. The book I recall shows the other dwarves paying immense respect to Thorin and that's another way Jackson could have got us to care.
Jackson should have learned by now that every time you deviate significantly from the script, you alienate your core audience. The female elf love plot wasn't the worst thing in the films by any means but didn't fit in with Bilbo's story.
LotR spent a good portion of time showing us beautiful vistas of the world. The Hobbit looked like it was filmed in the world's smallest studio with extremely dodgy lighting. This made the dwarves and the goblins look ridiculous.
I truly wonder how much of this could be fixed by a fan edit. Obviously you can't change it to Bilbo's perspective but you can remove anything that doesn't make the audience care. Use some filter or even blurring on the overlit scenes. Make the barrel and Goblintown escapes look less stupid.
Much of the third film was excellent -- if you like battles.