I think I'm a case where if I am interested, I will have some fandom involvement, but it will be occasional and not heavy into the active community (though given that a lot of the active community is on Tumblr and I'm not, I won't get involved in that anyway).

The best example I have is also a kind-of reverse of what you've asked - I watch GoT reviews, recaps, theories and explanation videos, read the wikis, read fic, but I don't want to watch the show or read the books.