you wrote “…someone who has been here for 5, 10 20 years, who is a good citizen…”
but they are NOT good citizens. they are not citizens, they are trespassers. i agree that as children, they are less responsible than they would be as adult trespassers, but trespassers they remain.
i would support a pathway to citizenship, but only one that acknowledged the criminal nature of their entry. i.e.
green card for ten (more?) years as a probationary period. if they can stay on the right side of the law, and not on public assistance, then (or during the ten years) they pay a substantial fine for their criminal entry. this would entitle them to a place at the end of the line for regular legal immigration.
any criminal activity or application for public assistance during the ten year probationary period entitles them to a fast ticket to their country of origin.