If children spend most of their childhood in school, they will become institutionalized. School is an institution, like it or not. To suggest children can spend 6 hours a day, every weekday for the majority of their lives, in school and not become institutionalized borders on magical thinking. It simply follows that committing to an institution is going to result in institutionalization. 

Saying this to school parents gets a very chilly response. I don't know why. If you choose an institution, aren't you asking for institutionalization? Is that not the goal? That is, in fact, what schools are paid to do and they do a great a job of it. Harm isn't implied, but cultural norms are created. We don't notice institutionalization so much when we are all equally steeped. But that doesn't mean it isn't happening. 

Profound institutionalization won't be true for every schooled child, of course. Parents who put their kids in school, but who maintain authority above the school system, seem to raise kids sheltered from the darker side of the lessons schools teach. Every child is homeschooled, after all. And homeschool is its own form of indoctrination. I think one important difference is that home indoctrinates love first and on a fairly consistent continuum. 

Love is antithetical to abandonment. A lot of children never get over this earliest of cultural dichotomies, when their parents hand them over, body and soul, to bureaucracy. We all love our kids. Be that as it may, commitment to an institution is going to result in institutionalization, in a fairly consistent way. I've known parents so dedicated to the institution of school, so institutionalized themselves, so full of the Koolaid, they bring it home, even into homeschooling. That's just sad.