I think that until I got involved in online fandom, I had no idea that the two kinds of writing were different things. Discovering the concept of idfic gave me a couple of "Oh, so that's what's going on there!" moments about things I'd read.

I don't think I'd want to separate them, though, because without the "I like this!" component, stories tend to be sort of... juiceless? I may admire them, but I don't love them. Without the thinky component - I think that depends who you're writing for. The more id-iosyncratic a story is, the narrower the audience gets.