A simple concern on this topic: When my day to day life is public online: a)strangers know when I am on vacation and my house is empty b) given the standard misunderstandings amongst people - what they can check about what I am doing via online tools and it differs from what they expect - and they never have to let me know they know (a seed for massive misunderstandings)

Both a and b open my life to problems out of my control. Irrelevant of the life I am living. Thus the need for privacy.