I really don't think they are apologizing for what they did/said or whatever. To me, they are apologizing because they got caught.
How many of the apologies are sincere? They are doing so to keep their 'good' name. Besides, it usually teaches them to think before they speak.
To me, if you are some sort of celebrity, all the cameras in your face 24/7 is part of it. Just my .02 worth.