Indeed, I'd see it the same way - for individuals (and indeed families) it certainly is not really more secure - if anything, less so due to the likelihood and encouragement for families to put more intimate/sensitive and personal details into the environment.

This and things like Pair, the social network for couples, I would suspect are shooting for high 'value' - where value is correlated with selling that information to third parties (advertisers, at best; but other parties are possible customers too).

edit - after reading their privacy policy, they do currently seem to have a good standing; even so I'd generally be cautious