If you'd bother to read the whole book, you'd learn that even the subsequent foster carer, "renowned" for her achievements with very damaged children, was unable to tolerate Alex. You would also have learned that everyone let Alex - and her parents - down completely.
The care services and the schools ALL - without exception - come out of it very badly. The adoptive parents do not. They were saints. I'm quite sure that 99% of us could not have persevered for so many years and that not even 1% of us could have shown as much love as they did for Alex. Anyone who has read the whole book is welcome to disagree with this, if they wish.
Please do not make judgments (which is what a review is) when clearly you have either not read the book at all or dipped into it for just a few pages. I too had my doubts (and condemnations about the impatience of the adoptive mother) in the first half of the book but ended up totally horrified at what the "care" system did to both Alex and her heroic adoptive parents.