Re: the above in bold - if they weren't from working class backgrounds to begin with, this would be less of an issue to some. There is some ingrained belief that people from each class should know their station in life and not put on "airs and graces" as some people (you being an example) believe them to be. My mother is also of that opinion - she doesn't like them, because she's a bit of a snob, not because she thinks they hid their kids' body.
No. I disagree with your Sentiment. The fact that some people 'better themselves' ( for want of a better word), should not be to elevate themselves to look down on people, the very people who lived with them, went to school,played in parks etc. The reason would be to benefit their families, communities etc. It is said that some of the queens stafff are more snobbish than she is. Also lower ranking royals have high demands as to how people should treat them.
I do not perceve the McCanns to be arrogant. It is how they come across. nothing to do with class, perhaps they have become doctors to mingle with their 'betters' who knows, but their demure and lack of social skills,and parenting skills, do not hold them in high regards as far as my social circle is concerned. Great scocial mix it is!
Take an example of missing people it was all about Madeliens mum...her little missing girl... no one else got a mention... apart from Amaral of course.