Suppose I'll be the first to say yes. As you can see, I'm always offline.
It's convenient for several reasons.
1. If I don't feel like talking to people but still want to be online it helps to show up as though I'm not. Going by past experience, I've noticed certain people get upset and feel like you're ignoring them if you don't reply at a certain pace. It's not that you want to ignore people (or are ignoring them at all), sometimes you just don't want to deal with them.
Of course there's the idea.. why don't you just tell them you want time to yourself?
That's a good point, but I rather not do so because even that can bother people.
I was going to list more reasons I do it, but I kind of blanked out.