No matter how good or caring they were, and how loving and stable a home they provided, WT and his sister were still foster kids. Not even adopted. They were under their care but ultimately were in the custody of the state and technically could have been taken away at any time, I'm guessing that knowledge would have something to do with it. Not that it was 'easy come easy go', I don't doubt for a second it's been a hideous, horrifying, heartbreaking experience. But I think that it would lead to very different feelings than it being your own biological kids. Or even adopted children, who might not be your blood or known to you their whole lives but are your own children, not the state's.
I cannot agree with this, some children are born of the heart, not the body, children's services or the courts, etc.They might have been foster children for a year or 16 years, that doesn't change the feelings of a parent, well, many parents.
Sometimes and more often then we care to admit, birth parents don't care, have no innate love for their children, that's why some prefer drugs, alcohol etc and we are seeing so many babies killed at the hands of their families. Then they cry and blame others.