First off: It's true. It's completely true (well, maybe not the superiority stuff, but that's beside the main point). Just about everything in metafandom is either non-fandom specific, or related to live-action western television. And a lot of what falls into that first category is written from the perspective of live-action TV fandoms.
Which is pretty frustrating for people like me, who love meta and want to read more, but don't have a lot of interest in most live-action western television (hereafter referred to as TV Fandom for purposes of not making me type 'live-action western television' over and over). I haven't deliberately followed a TV fandom show that was currently running since I dropped out in the middle of Doctor Who season four. Everything I've watched since then has been old shows or re-runs that happened to be on while I was at work. Why? Because almost nothing that's currently running is at all interesting to me. The only thing I really want to watch is Deadliest Catch, and I have three more seasons to get caught up on before I can start watching new episodes of that.
I don't blame metafandom's mods for that. It's not their fault. If the links aren't there, then it means they aren't being sent to them, end of story. But why? I know the meta exists, I've seen it! However, I think there's a recursive loop at work here: Lots of TV Fandom stuff winds up on metafandom, meaning more people in TV Fandom hear about metafandom and follow it, meaning more TV Fandom stuff is submitted to metafandom, meaning more TV Fandom stuff winds up on metafandom.
And so on.
I suppose this problem could be addressed by creating an alternate metafandom for non-TV Fandom stuff, but...I don't think that's necessary. The system that's in place now will work fine for non-TV Fandom stuff, too, and has an existing audience. I don't see any reason to create competition. Instead, I encourage you to try and reform it: If and when you write meta about non-TV Fandoms, please make a point to link to metafandom! I know I am. A greater balance between fandoms in any pan-fandom activity is always for the best.