The main reason people stay in the furry closet is because they fear their family or friends will shun them for it. As I've mentioned before, I've got myself a wonderful family and great friends. So it's common for other furries to wonder why I don't come out and tell people about my "peculiarities."
My case isn't as regular as other furries', I don't believe. First of all, I don't really consider myself to be a furry, since furries are the people who enjoy conventions, fursuits, plushies, and the like; the fandom part, if you will. You can imagine how hard it is to relate myself to a fandom I'm only slightly part of. Now imagine how hard it would be to explain my "peculiarity" without having much of anything to relate to, besides a fandom I'm hardly involved with. My logic: If I can't explain it, I don't expect anyone else to understand it.
The other reason makes more sense, though it's almost ironic. My family would never throw me out, make fun of me, or be embarrassed because of a personal difference. However, they won't ignore it either. I'm sure they would try their best to understand, though I doubt if they ever fully will. I don't tell my family because I think it would be too hard on them verses on myself. It would kind of ruin things for them if they are reminded of my bizarre trait every time they see cartoon animals on TV.
As for my friends, I'm sure they would be cool with it. Especially if I explain clearly my situation and opinions, so that they know I'm not into what they (and myself, for the most part) would consider crappy. No offense, though; it's just that not everything in the fandom is... well, you know how some of it is. I don't tell my friends because there's the whole reminder part again; every time an animal appears on TV they remember my difference. No way I'm messing up their lives like that.
I've read a lot about people wanting to come out of the closet or help their parents to understand. It's always a conflict of acceptance with the victim's reputation at stake. Well, what about the friends and family of the victim? Don't they have something to lose? Isn't it hard on them if the victim isn't who they seemed? I say victim because we don't always choose to be; it comes to us. Or, at least in my case... minus the furry part, since I'm just part furry...
Dang it, what am I? Or is it who? Blah! I ask you not; I talk to myself!
PS: Why are some people really bad at hiding their secrets? I have locked boxes, passwords, filters, erased history, hidden files... and I keep my mouth shut. Really, it's not that hard if you try.