I do not know how this particularly works in the USA, but in most reasonable countries I know of, the ways in which anyone (company/government/etc) can interact with anyone who isn't a legal adult are limited. For good reasons too, I believe. I think it even is dictated by signed/ratified international treaties/declarations, but I don't recall any details right now.
I'm pretty sure that the tracking of minors (or the unborn), essentially surveillance, is actually in violation of the legal protections those are supposed to have. I've heard plenty people argue that this tracking is somehow admissible, if their legal guardians sign off on it. Often based on the assertion that legal guardians are responsible for those under their care. However, the legal protects of minors are a thing on their own. As far as I know, guardians can not "give away" the legal protection of minors. No more than any person can "give away" their inalienable human rights (also not by consent), which is what makes them inalienable.
So here we have an industry that in all likelihood is seriously violating the legal protections that minors (and arguably unborn too) are supposed to have. Instead of demanding that governments address these rogue corporations, which considering the systematic nature of their violations probably even warrant to be classified as criminal organizations, we instead listen to what key people in this industry say in an attempt to justify their actions, or suggest as remedy for their behavior.
I'm not really all that shocked about people like Schmidt saying such things. About as predictable as a politician talking any kind of bullshit that will sell their agenda. However, I am appalled that this industry gets away with what it currently does. To me, that says a hell of a lot about the system, and how it apparently prefers to protects these interests instead of protecting the people it legally is supposed to protect.