I am really interested in the new schooling trends although I don't find "traditional school" as something intrinsically bad (typically, everything depends on people who work at school and parents being ready to cooperate with teachers and with each other). So I made an effort to go through that long elaboration and here is my 2 cents.

The claim that current school system "is based on a system that was developed over a hundred years ago to prepare people to be Prussian soldiers" sounds strange. Maybe that was the case in Prussia, but there is quite a lot of countries that didn't have particular reason to follow the Prussian way of education.

Another important thing. This school is not a school. "Pathfinder isn’t actually a school. It’s not accredited and doesn’t have a state license". Legally kids that attend this school are homeschooled so all the responsibility for passing legally required tests lays on their parents. It is hard to say how much work parents has to put into actual pupils preparation and what are results as compared to traditional schools.

This schools is also a private, paid school. The price and ability to pre-selects (recruit) kids automatically filers out many "problematic" kids. Public school system does not have such luxury, they need a system that will provide some way of dealing also with kids having various background (including aggressive, non-cooperating kids with parents with the same attitude).

It is easy to have "open" education and "free" collaboration without any "Prussian discipline" when all kids are smart and well behaving and you have parents that take active part in the education process.

"Consider that every county in America has standing armies of professionals paid to teach children how to read. Then consider that Sudbury Valley has no reading instruction whatsoever, yet its graduates all leave campus perfectly literate." The question is what would happen if they got kids with dyslexia, serious problems with concentration, luck of support at home, etc. Wouldn't they need someone from that "army of professionals" to actually figure out how to deal with such kid?

Next it seems this kind of schools fail often "Wilder says. Sudbury schools have a high failure rate. So, too, did the previous generation of free schools that arose in the sixties and seventies, characterized by their “brief life spans and the often loosely defined nature of their educational practices,” as one study put it.".

Apparently something is not working that well, although their approach sounds very cool and people behind that particular schools seems to be passionate about what they are doing.