What you're describing is an off-shoot of what is called "elitism" on electronic media. As people invest more of their time into any given subject, they will then begin to take on said subject as one of the defining characteristics of their personas, up to becoming a foundation of such. When such a sizable degree of their sheer existence is determined by the subject at hand, the fabrication of their social interactions begins to use the subject matter as a replacement for more everyday, run-of-the-mill equivalencies. To the outsider or to the objective POV, this appears as taking one subject entirely too far; however, to the individuals actually doing such, they are discussing all walks of life, be it friends, family, love, success, failure, oppression, etc. through their subject-centric discussions.
A "star wars is junk" thread may appear to you and most as such, but to the individuals heavily engaged in such, they may as well be discussing the predictability and lack of attraction to the typical cookie-cutter socialite female.