I'd rather have people sticking to books they can understand, as opposed to trying to actively discuss and rave about books they have no chance of grasping.
Well, that's incredibly pretentious. First of all, I don't think it's very common for people to rave about books they don't understand. Second of all, why would you discourage anybody from seeking out and talking about good books? Get off your high horse
I'll agree with your first point as a general rule, but I have heard many people discuss books that they clearly haven't understood. It may be the culture of the high school I'm attending. I wouldn't say discourage is the right word, because they're welcome to try, but if people are content to stick to reading young adult fiction I see no reason to try to push them into the world of literature.
Yes, but they're currently among the most popular. Besides, The Hunger Games and Harry Potter are great books.