For me, it is a question about “product purpose.” 
I mean, everyone is able to just start a new topic, like, e.g., “The Sarah Jane Adventures appreciation thread”. That is more or less a TV Club thread minus the structure. Should I take up watching SJA again, I will just post there. Same with K9 - How?!?! Why?!?! .
So the question is, what is the USP of doing a Club?
I think it’s about gathering enough people who participate at the same time and have fun discussing stuff they watched/read at the same time with other people. People being able to add posts later on is fine and good, but the differentiator to any other thread about episodes, books, etc., is the concurrency. That’s why the clubs are fun, not the starting of threads that, over time, will be filled with content.
So my conclusion: We already have the “many as you like” option if we don’t care if there is more than one user at any given time who actually watched, read, etc., the stuff recently.
And so, I think more TV Clubs only make sense if there are enough people who want to participate. If not, it’s no problem to just post one’s thoughts in What Are You Currently Watching? or similar threads.