I can't speak for others, but I wasn't saying I mind people posting happy news -- I just prefer if they simply do so without trying to make it look like something else. I.e., bragging is better than humblebragging. And whining is whining, and PA is PA, on Facebook just as anywhere else.
And I do think that it is nice to be judicious about how often you post even happy news, the same as you would at a party.
Miranova, I don't think there is anything wrong with any of those examples you give, even though not everyone will be interested. The only problem is that when people post things not of general interest too often, then everyone's news feed is cluttered up with stuff they aren't interested in and they won't bother to go through it to see the things they do want to.
Which is why even perfectly nice people who aren't vaguebooking or bragplaining or whining or anything else eye-rolling get unfriended or hidden by lots of people. I just don't want that many posts from any one person, otherwise my "news feed" starts to become more like their personal blog. In fact, maybe starting a blog might be a better choice for people who post so frequently on Facebook.
Stepping back and thinking of the original post, I think the underlying issue is how we use Facebook, specifically (for an etiquette forum), are the rules and standards different from how we would communicate in other situations? SingDanceAct compares party conversation; others mentioned bulletin board. I think we can all agree that there is a big difference in what is appropriate subject matter and frequency for party talk, a bulletin board, a blog, and a diary. So where does Facebook fit in?