Someone who cynically grandstands about their unpleasant childhood, by way of fishing for pity or giving an apologia for their heartless or anti-social behaviour. Very trendy in a postmodernist climate. From the character in Dickens' "Hard Times".
Look at that kid on the TV saying that he wouldn't have killed the kid on a joyride if his own mummy had loved him a bit more. What a perfect little Bounderby.