I definitely agree with you, but my motives are a bit different. I most definitely write what I do because I like it and because it interests me and I adore the characters, and I wouldn't have it any other way. But I post fic publicly because I am interested in what others think (though I tend to disregard the people who only spew copy/pasted praise and demand updates). I have many fics that are not posted publicly and probably never will be, because I either feel they're inappropriate to share or I have no wish for feedback or for other people to read them. But I know that I'm kind of strange in that regard... XD

There was a Mir/San site called Yakusoku to Negai that I stumbled upon early in my forays into IY fandom, but updates were really, really sparse, and now it seems to be gone altogether. I haven't found any others, though that doesn't mean there aren't any out there. I have the know-how and whatnot to make such a site, but I'm not sure I have the resources or the time to do so...