Right
In answer to the question...
I actually think Anthroposophy is fairly odd. I don't particularly agree with a lot of the 'rationale' behind their beliefs. I (and most of my Steiner educated friends) spend many many pissed happy hours taking the piss out of the wackier theories and teachers. I don't consider it to be in the slightest bit 'secretive' - dd's school are forever running talks and special offers on books, and the teachers will answer any questions asked of them.
But I consider it to be the best education for my child. It is a truly informed choice. I spent six years at Steiner school (from 8-14) and both started and finished my education at state school, so I have experience of the good and bad in both systems.
Anthroposophy may be behind the education, but it is not actually introduced to the children. So there may well be crackpot hardline Anthropops who think that a devil speaks out of the tv, but that is not a concept that my child will be made aware of.
I'd say that only about 25% of the parents are Anthroposophists - most of the rest are well aware of it but choose to simply take what they can from the education on offer and leave the anthroposophising to those who are interested. There are some parents who don't appear to have a clue what the school is all about, but tbh I think thats just lazy parenting rather than the fault of the school for being 'secretive'.
I have to say that if there were an school like Steiner (no formal education til seven, outdoorsy, anti-tv etc etc) but without the Anthroposophy, I'd probably choose that instaed. In the absense of that, I have chosen Steiner for my child. I have not done so in ignorance, and having made that choice I do my best to support the school and what it offers to my daughter.