Self discipline in public schools equates to... sit still, be quiet, March in a line, don't play good vs bad on the playground, don't ever get hurt, and do what everybody else is doing.

My experience with one Waldorf school, which is possibly similar to Montessori, is they *act* as if they're laid back, but they're actually very rigid in a passive-aggressive way.

That is exactly my impression, admittedly not on a lot of research.
Can an education system be of any worth if it does not promote self-discipline?

Funny. I've hear they're relaxed to the point no learning. No direction. Maybe my sources were wrong.

We interviewed the Montessori school, Waldorf school, and another school. We chose Waldorf but ended up in a lawsuit with them, the first time I've ever been a party to a lawsuit. I liked the idea of Waldorf, but not elements of how it was executed. Montessori seemed indistinguishable from me, even after reading materials from the school that were supposed to highlight the differences.

We ended up at a public school. I think we just lucked out with an amazing non-nonsense teacher and principal. The teacher comes dressed in good clothes but clearly dressed for the hard work of teaching 5-6 y/os. Her husband was a marine and is now a police officer. I get the idea that both of them have heard a lot of bogus excuses and know how to handle them. My kids loves her and the school. Next year we could be in a completely difference situation. There's no substitute for staying on top of it.

I have read some things about Montessori education and don't remember a lot, except that I found it rather rigid in outlook and practice.

I've read some things about Montessori and agree with most of it. I'm not so sure the Montessori schools of today are really in alignment with what she wrote a hundred years ago (or whenever it was) though. From what I've heard of them anyway. I wonder of the school staff has to study her ideas before they work there.