Fordim,
While I entirely understand the response of the females in your class to
Treasure Island (I am sorry, but I have never liked books involving ships and the sea -- I loathed
Moby Dick and
The old man and the Sea , too), I share your horror at their dismissal of TH as 'a boy's adventure'. While it would probably get you fired to say so, it sounds to me like the girls are being a bit sexist!
1) what these women are talking about?
Okay, it sounds like they find TH as unengaging as Treasure Island based on the fact that there are No Women. There's nothing you can do about the characters JRRT used in the book.
An additional factor may be what they have been used to reading. One of the great disappointments of my life is that my girls have never indicated any interest in the good literature I and my parents have tried to provide them with over the years. They rejected
Swiss Family Robinson (the greatest non-Tolkien kids' adventure book
ever!),
Little Women, and
The Secret Garden among others, instead preferring to read drivel like the Babysitters Club. I have no idea how old your students are, but if their formative years were spent reading books where the big conflict is if Susie should 'fess up to sneaking to the beach without permission, then yes, TH and TI are both going to be more intense than they are prepared to deal with. Again nothing you can do about this.
2) why you like the book, despite your being a woman?
A great deal of my affection for TH, and eventually to Tolkien in general can be traced to my introduction to the book. An otherwise vile sixth grade teacher concluded that my class was the perfect captive audience and read it aloud to us over several months. She was an expressive reader who made the characters come alive. We also discussed the book at points, so were made aware of how Bilbo grows and develops as he leaves comfort and civilisation further and further behind, and Tolkien's use of different characters and situations (at least as well as eleven-year-olds could discuss those subjects.)
3) how I can present The Hobbit in class in such a way as to engage those women who find it so unappealing?
Seriously, do you have time to read any passages aloud? I finally read TH to my younger daughter and that did the trick. She loved having me read it to her, -- we went on to FOTR and are now part-way through TTT. Even my super-cool teenager would come in to listen.
Don't let your students read alound first unless any of them are also good expressive readers, or it will come out "Blah blah hole in the ground blah blah hobbit" or "Inaholeinthegroundtherelivedahobbit." Maybe introduce the book by reading the first paragraphs aloud? Perhaps offer to let your students read passages as you go through the chapters? Read a wee little section each day to start things off? I know they aren't as young as I was, and my daughter is, but TH is a delightful oral and aural experience at any age. And it's fun to make Thorin sound a bit like the Grand Poobah.
I don't know if any of this is at all practical for your situation, but I hope there's something there you can use.