I suppose that people do what they want to do, but it's so transparent when someone makes a post that is clearly intended to be read by someone, perhaps because they don't have the wrinklies to say what they mean directly to the person's face.
That's one thing the Internet has been generally good for in some cases though, at least enhancing communication. I look at how high school kids now have a couple more "safe" avenues to communicate (e-mail, IM), and it's probably a good thing. The only negative is that some kids are even bigger social retards when it comes to real life human interaction.
Me, I tend to just write whatever's on my mind. I admit that I've written stuff that might be read by people I'm talking about, but generally it's not anything I didn't already tell them directly.
As I told another friend who is known to post specifically for someone to read (which generally leads to drama), I think it's a cop out. Face to face is always much better to me, especially if it's something dealing with a spouse. Unfortunately, this person can't seem to have a confrontational face to face.
I know you don't like LJ, but the advtantage LJ has for me is I can lock entries that are way too personal for the world to see, but I still want to get down onto "paper" so to speak.