The House with a Clock in its Walls, by John Bellairs, 1973, Book Review

This book was odd. Recommended to me by a friend, I had high expectations that simply weren’t met. It starts out with ten-year-old Lewis Barnavelt on his way to his uncle’s house after his parents’ deaths. Uncle Jonathan is a minor magician, and he lives in an old mansion formerly inhabited by an evil wizard. Strangely, the walls in the house tick. Jonathan’s neighbor, a peculiar old woman named Mrs. Zimmerman, also dabbles in magic. Together they try to learn the old house’s secrets.  At one point, Lewis dips into one of his uncle’s forbidden magic books, then he and his friend sneak into the graveyard to try a spell to raise the dead. Their success nearly leads to the end of the world.
I didn’t care for the dark tones in this book. The whole setup has a bizarre, creepy feel. Yes, Uncle Jonathan and Mrs. Zimmerman are good wizards, but they are so odd. But I never warmed to them (or any other character). They have strange personalities and do odd, random things. I never felt I had a handle on who they are or why they did what they did. They didn’t make sense. And some plot events, like the time the three are chased in their car in the middle of the night, are never explained. What was that all about, anyway? It just builds on a series of weird events that don’t really make a solid picture at the end. It feels…disjointed.
It was fairly predictable. I didn’t like the characters. The pictures were even stylized in a way that didn’t appeal to me. Twice it put me to sleep. I almost didn’t finish. I don’t usually rate books on here, but this one gets a two. That’s mostly because the suspense was okay and the old mansion was really cool. So why did I bother reviewing it? Because I know this book has been highly acclaimed and the series has sold well (maybe later books explain some things?). But I just didn’t get it.
How’s the content? Wikipedia calls it “children’s gothic horror,” though it isn’t terrible. A dead person comes to life via a spell, but most magic is innocent. Scenes from Harry Potter are far worse. Lewis’ hand is once guided by an unseen force. A Ouija board is mentioned but not used. It’s mostly creepy hype. I think there may have been one mild profanity, but I’m not sure. Like I said, I fell asleep twice and had to reread portions.
Can you tell I was disappointed?  So, has anyone else read The House With a Clock In Its Walls and liked it?