Personally, I'm in favour of good, long biographies.
Partly, that's because just listing the bare essentials (birth, marriage, death) barely even begins to touch the surface of what makes a person interesting. I felt this particularly when my dad died. He had been essentially "shut in" for about ten years, and he wasn't very articulate in the end, but he had made a lot of important contributions (and not just to our immediate family, either), so I felt a strong urge to explain to the world just what kind of person had just gone out of it.
And, partly, it's an aesthetic consideration. On profiles where people are actively posting comments, it's easy for those comments to run way longer than the actual biography and related information, and that just doesn't seem right to me somehow.