I get tired of hearing phrases like, "you have no promises with birth children either." While the intent is good and it holds some truth, it is not completely accurate. Birth children can stray and go bad, but none have another individual who can rightfully have a claim to your role. I have to constantly deal with the fact that another man claims the role of "father" to my exclusion, in spite of my attempt to be open to him.
This has greatly contributed to my alienation with 2 of my children, but is unavoidable. I believe the father is still the one who raises a child, but I have to content with someone else. That is not true when a birth child "goes bad"!
It is a rough path and words that minimize the negative impact don't really help, they just trivialize things and leave people in or open to more pain. It would be much better to deal with the reality that many of the children in the foster care system will never bond with a "good" family, no matter how much they need it.
Tough truth, but better to deal with the truth and learn how to work past it rather than to deny or ignore it and be sideswiped!