In fact it will be a weird question. I know why girls need to be seen offline on lush, because many guys distract them. I always try not to bother my friends.
But if you need to hide, why do you add people? What are your reasons to be seen offline? If we know reasons, we can be more careful :-)
I have asked this same question before and was told it's because they either have "stalkers" or those that message them obsessively every time they are online causing unnecessary drama for them. For me Id simply block the unwanted person instead of hiding. However, sometimes I can understand wanting to log on to read stories and not be bothered so appearing offline to friends would make this easy, but that's my opinion.
Different reasons for me. As a story moderator for Lush, I'm not always here just to read or chat: I work here. I'll often go invisible just to get some stories done, and to catch up with mods behind the scenes. As far as stalkers go, well, that's what the "Block" feature is for!
"Good writing is supposed to evoke sensation in the reader - not the fact that it is raining, but the feeling of being rained upon." -E.L. Doctorow

I generally just ignore people I don't care to chat with. I suppose I'll eventually get tired of it as many other ladies have. I feel sorry for all the decent men on here though, some girls just group all men together(and merit-ably so given the ratio of assholes to gentlemen) and don't desire any interaction at all.
I'm here to do more than hang out. When I think I have time to shoot the breeze I'll be online and visible. But I also come here to Publish (which means spending time writing/editing in the Lush editor). And other times I'm here to work with other authors to do things like edit and collaborate otherwise. I don't like to chat while I read sometimes. And other times I'm here only out of interest to chat with a friend or two.
My life, my time. I do whatever.
One thing guys dont realize is the sheer number of guys who will zip the gals a black box if she's on. I can log on -walk away to get a cup of coffee - and come back to a line of black boxes. 5, 10 people all saw I logged on.
I've taken to staying invisible by default purely because of the sheer amount t of attention I can get. I don't dislike it. I love chatting and saying hi - but I don't have time to chat with 10 guys at once.
I would agree with above posts. Sometimes I'm not in the mood to chat and sometimes I don't have time - I'm just popping on to read my mails, etc. I know personally I'm incapable of holding more than one conversation at once, so it seems more rude if I am talking to one person if I ignore anyone else who messages me simply because I am caught up in the conversation. I'd rather go offline so I can focus on chatting to one friend, or reading a story.
for me, it's a question of the damn sound that it makes when you get chat requests.
when you're a gal, the requests come constantly from people you've never talked to before. it would be one thing if there was just a little notice bar, but that sound, over and over and over, is not only fucking annoying -- it's fucking LOUD. so loud that i either have to turn down spotify to the point where i can't hear the music i want to hear, or alternatively, loud enough where i can hear the music but that damn chat notice gives me a headache.
same deal with the chat room "uh-oh!"s, fwiw. love this site a lot, but wish they'd change the lush sounds or turn down the sound volume. they're seriously fingers on chalkboard to me.
Big-haired Bitch/Personality Hire
Most people see the 'online' status as being available.
Sometimes I'm just here to read. Sometimes I'm just here to enjoy the chat rooms and not really hold any one-on-one conversations that people try to initiate when they see you're online.
And as someone else said higher up, sometimes I'm just here to handle mod stuff, which sometimes entails correspondence with just about any given number of members simultaneously.
Overall, I show up as invisible because I like to control who I interact with and when, without having to worry about a barrage of black boxes or private chat requests.
"What is the quality of your intent?" - Thurgood Marshall
If I'm enjoying reading I find interruptions annoying.
Same if I'm reading Lush stories or the forums.
it's easier to just come on invisible. that way i don't worry about offending anyone if i'm not in a chatty mood.
That is really easy. When I want to chat, I turn on the visibility. When I am in the mood for reading some stories, or being on the forum (like right this moment, for example), I have the settings to invisible as I don't feel like chatting. Often as soon as I sign on and I am visible, I have four or five people poking me and wanting to chat, and I can't respond properly to everyone. Plus if I am going to chat, I want a coffee or tea in my hands. I have signed off many times from chatting with friends to get a coffee.
I usually am on invisible because I have the same people send me 5-10 message in a row and they continue to do so. And just because I'm on the site doesn't mean I want you to necessarily have strangers calling me babygirl or slut or sexy constantly. It's different for everyone, some people come on here just to chat while others come to read. A private message usually gets a better response from me