Warning: You are about to read a very unhelpful post.
I have to admit I don't like
The Hobbit much. The first time I read it, when I have been a member of the Downs for quite a long time, I fell asleep before finishing the first chapter. The second time I did - a looong time afterwards - I managed to convince myself to finish the book by telling myself that I don't have the right to call myself a Tolkienthusiast

without even reading it. Sure, there were sparks of enthusiasm in a few parts of the story, but nothing really stuck. So, stone me if you will, but I barely remember what TH is really all about. (Maybe for this reason I should join the next CbC.)
Up until now I still can't pinpoint exactly why I don't like TH much. Perhaps it's because in my mind I have stereotyped Tolkien as a writer of LotR-ish books (whatever that means), and there was a sort of culture shock when I realized that the same author of LotR wrote TH. It's weird and unfair to say the least, I know, but it could be the cause.
Or probably it's because there's no specific issue that I can sympathize with. I prefer to be able to interact with a book I'm reading, and for me TH just doesn't reach out and whisper, "Come, let me know how you feel about this." It's all "Come, sit back and be the audience." No offense intended, of course; this is all my perspective.
Now I also don't think that literature should be categorized according to age, as there are a lot of people who do not think their age. (I've 'met' quite a lot here in the Downs.) As for the gender issue, it's all very relative. Though, for example, a certain story only has negligible female characters, if the male characters deal with something females can understand or relate to it would probably be easy for them to appreciate it. But who knows what goes on in the mind of a female?
As for the last question, you can probably use the scholastic merit of your class to scare them into appreciating TH.