Eh. It's one of the very most important events in the life of one of our best contributors. There might be a better venue for this, but I don't think it's a big deal, because I don't foresee us tumbling down a slippery slope made of baby. It's useful to us to know about central life-changes in the top LW writers, and 'I had a baby' is one of the most informationally compact, least slippery-slope-prone bits of information to find out.

Plus it encourages us to build stronger social ties to other LessWrongers, and to consider what this is all for. The only extremely obvious reason not to make a post like this is that it might lead to unpleasant arguments about the relevance of the post.

If there's a clear problem with Stuart's post, it's that it has a deliberately misleading title and introduction, so it's harder for people who aren't interested in personal stuff to know to skip it.