Something I've seen and even bought into until I became an adult with my own thinking is that society likes to stigmatize kids who are in foster care or who were adopted. I didn't even realize I bought into this.
They are seen as less than, unwanted, and often times "behavioral." They are labeled "the bad kid" by peers and even adults. Sometimes we don't even realize we see them this way, often it is implicit and subconscious bias deep within us...that's the trouble with our society. Things are engrained into us without even realizing it, and these things continue to churn the way our world works, spinning abusive and unjust cycles.
And sure, many of our kids's behaviors hurt other people. That is real. But, I'd argue that every single kid hurts another person with poor choices; they're all developing and learning what is okay and what is not.