Sorry, I don't read it that way. I think he points out that they have no doubt that Amanda is guilty as sin, and then complains about a lack of sympathy from Amanda's family. I have already agreed he also complains about the media attention on Amanda and the celebrity status give her as well as the lack of focus on his own daughter.
I call this twisting his statements, to misquote his words changing them in order to criticize them.
I read howevr that there is at least a change in verb, from "whines" to "complains".
But still, there is a twist and misinterpretation by removing parts of the meaning that are pretty obvious. To avoid ambiguity, I want to pint out that what I clearly understand he never wishses to have more sympathy from Amanda's family, and doesn't expect sympathy.
So he does not complain his family doesn't have "sympathy". He rather complain they didn't have "sympathy" in the past years.
Moreover, it is obvious the purpose of his statement is to express his position to the public, not to dialogue with Amanda's family. Therefore, I cannot subscribe to your perception that his statement is contradictory. His article points to the attention of the public a reality about the behaviour of the Knox family, his point of view about the behaviour of the Knox family, and this just as effect of the need to take a position in contrast to the media point of view conveyed by Knoxs' exposure. Mr. Kercher wants public to perceive that there is another point of view that lack attention, that his perspective is different, and thus wants to insert his feeling and judgement to correct the story.
The fact that the Knox family appeared callous is, right as you can read, stated as a fact. A true B-side of this story, something the readers might want to know as they watch Edda getting emotional on tv. Kercher is a journalist, he doesn't write to whine, but to contribute in building a reader's critical perspective.
More interesting to me was the explanation given by the Knox family.
They didn't say they were cold with the Kerchers because the Kerchers thought Amanda was guilty. Not at all.
They stated instad something really more catchy and more self-blaming. They said that they didn't contact the Kercher in order to not add to their pain. Thus admitting they didn't speak to them because, had they done so, they would have produced a negative effect on the Kerchers rather than a positive one. They admitted that bringing their sympathy and condolences would have been worse. This alone is descriptive of the quality of arguments they think they have to communicate with the Kerchers.