They shouldn't have to, but surely it would be better for the family to just release a statement, that would stop all this idle speculation, and make the media parasites move on. It's not about right or wrong, its just the way the world is now.
In fairness, the family have allowed information to be leaked out, between the lines in the comments that they haven't refuted.
From Brawn's comments that he didn't want to bother the family, to Brundle (who speaks to Ross more than Mrs Brawn) saying that he wished Schumacher could've seen the Malaysia race, to Webber saying Vettel was massively affected by Schumachers injuries.
Added to the reports of a 24 hour care facility built within the family house, to the family denying reports that his condition that he's even had so much as a rudimentary improvement, to even so much as the increased public appearances of the family you can make an informed guess as to his condition.
The likely reality is that his family and close friends have grieved the loss of Michael Schumacher in all but physical form and are trying to move on with their lives, as must those who never knew him. That's not to say he should ever be forgotten of course, but equally I don't see how the family going public and letting everyone know as much is in the public interest. They might be 'famous' but they are still entitled to some privacy.