I agree, and sadly this kind of gives the Montessori label pretty limited predictive value. Turns out you just need to find a good school, regardless of label.
It really comes down to the teachers skill and personality- and that often comes down to if the school can afford the best teachers. Often in the USA regular public schools in wealthy communities will have better teachers than you will find at most private Montessori schools.
Part of schools "affording" the best teachers is not money, but the amount of discipline problems they need to deal with. Which correlates to the financial status of the families at that school. For tons of reasons.
Which families tend to win the lottery to go to these schools? The parents that can afford to. Even if the school is free, the transportation is often not. Plus the parents have to have enough free time to be aware of the lottery for their 3 year old.
