Well, I don't know what you meant by "marked"; but it was neither marketed (it this what you meant?) or written for children, regardless of your personal opinion of it. That's all I'm saying.
Indeed it was "marketed." typo. I'd hazard a guess most people, specially the ones on this board read those books in middle school/high school. Like Jurassic Park and Congo. Marketed to children or not. They're not exactly "difficult" books, like Chronicles of Narnia. That's what I meant. The original Star Wars wasn't meant for kids either, at least not the first two films. Return of the Jedi is heavily criticized for being more "kid friendly." Yet at any rate I saw and fell in love with them when I was like 6. They've held up through time, but it doesn't mean they didn't hold some appeal to a younger audience.
Since The Hobbit was a children's book, I'm sure those who grew up with it loved TLOFTR that much for it, specially since they were still kids. That adults can read them too doesn't negate that... like Harry Potter. How many adults love those books and read them as adults, not kids? I recently bought the 4th and final book in The Giver series, Son. I read all The Giver Books as an adult, but clearly remember the "advanced" readers club in sixth grade read it.
In short, I agree with you that the original marketing may not have been children, but I still say its main audience still ended up being just that, intended or not.
Since this is the now WATCHING thread however, I guess I'll note that I just watched the Halloween sequel. I enjoyed it, but far from loved it. I liked the nods to the original, as well as other minor details. Since we are supposed to already be familiar with the characters and story I forgave it's quick pace, but would have enjoyed a slightly slower burn. Like many here, I liked that Michael went back to his "pure evil" self, but the killing everything in sight bothered me. Part of the allure of the original is that he had specific targets and was more of a cat and mouse game than a kill them all bonanza. At any rate, good shtuff.