Boglach, am off out, so will rejoin the thread later, but just wanted to say thanks for starting the thread - I totally agree with you.
Am with you on the cognitive dissonance as well - Having grown up in a fairly abusive environment, I still have to frequently contend with my families 'fantasy' version of our family dynamics - it's very hard work!
An example of Cognitive Dissonance in action: I was abused by a family friend. Rather than face up to the reality of what that would mean for me/our family/my parents social circle/their standing as middle class professionals, it was easier to write off my subsequent 'acting out' and emotional trauma as mental illness and ignore the abuse accusations.
It's a pretty extreme example, but broadly, it's the idea that in order to protect their belief system, people will ignore or 'bend' conflicting evidence so that they can continue to feel comfortable with the way the world works. In my parents case, it meant deciding I was mentally ill rather than facing the possibility of their family being touched by abuse.
I do think part of the problem though us that a lot of people that I've met seem to have a fairly narrow view of what actually constitutes abuse. They view it as either beatings or sexual abuse and seem to have much less understanding of the effect that psychological abuse has on children. My ex was hugely damaged by years of put downs, criticisms and neglect, but if you told his parents that, they'd think you were crazy. As far as they were concerned, they were just loving parents doing the best they could (which is probably true)
Sadly though, some people's (my parents being a case in point) 'best' or 'good enough' is pretty poor and actually can be quite damaging.