I worked in a children's and YA library for a year, and picked up lots of those books and read the first few pages. So many placate the reader as if placating an abysmally stupid little person. "Let's Junie B Jones them to death."
I recall several parents strictly forbade their children to open "the dark covers of Harry Potter." Because witches are evil and evil is contagious as influenza in a warm, wet climate. One homeschooling mother would bring in her child weekly. His legs and arms were shackled and pinioned by chains woven out of misinterpreted verses from the Old Testament. Kid made a racket coming into the library and up the stairs. His mother had a pale, stern face that promoted sterility and fear. In her spare time she tortured question marks.
One day while Mother was distracted by a fanciful picture of an alien, the kid drudged his way to the YA shelf where I was putting away paperbacks. He asked for a good story. I picked out Lord of the Flies and told him it was about a bunch of schoolboys his age who wash up on an island and then proceed to gradually go wackball nuts.
As soon as he touched the book, his Mother's question mark alarm went off. The poor kid's chains turned molten red, and he gibbered in pain, dropping Mr. Golding's wonder as he collapsed to the floor. A black shell like chitin emerged from a pore in the back of his neck and cocooned his entire head while he jerked on the floor like an epileptic cockroach.
His Mother glided over to us like a Sith Lord. She hooked a silver leash onto a loop on the cocoon and dragged the boy past me, down the stairs. She left an absence of curiosity in her wake. All of my good ideas were singed away like sweat in a frying pan.
Digression aside, I agree with what you wrote, Gary. Although I haven't read Twilight, I have read Rowling's stuff, and I'm guessing that it isn't just that Meyer's characters may have weak motivation, Rowling is probably just a better, more inventive writer. The Harry Potter books have tons of references and descriptions of humdrum high school moments, but Rowling's shining feat is weaving an original wind to revive that humdrum and make it quite, quite wonderful.
The best writers resuscitate.