That's understandable. I wish there were a way of separating these two types of book clubs then, a casual versus hardcore variety. I think by doing so, fewer people would be disappointed when it turns out to be the opposite variety of what they expected. Thanks for your viewpoint, it helped me understand the idea better.
I don't think it's difficult? It's just in the way it's described.
> Monthly social book club, not too serious, new faces always welcome.
> Monthly book club exploring everything from X to Y with a focus on Z. Newcomers wanting a place to discuss how P Qs R with like-minded friends always welcome.
I expect you would feel very alone in the hard core book club. The socializing aspect with book clubs and any other hobby clubs are very high. Some people just looks around to find anything at all that helps them find someone to talk to, be it hobby train modelling, sewing or whatever. Book clubs are nothing special in that aspect. And most clubs are happy to get anyone, not just hardcore enthusiasts. Much like the church, they see it as an opportunity to sell their services.
Book clubs are generally going to be fairly causal affairs since they're clubs. If you're looking for something serious find a study group or a book club that calls itself a study group. Book clubs are like many other clubs, where social bonding with the group is expected, and the book's an excuse to spend time socializing.