There are plenty of ortho schools in the US (mostly on the more hareidi end of the spectrum) that make various requirements of the parents (ie that they are shomer shabbos, not have a TV, dress modestly etc.) What good's an education at school if the parents don't live at home the same way and present the same lifestyle and values to their kids? The policy makes sense. And it's interesting that Haaretz only writes articles like this-- about one anonymous kid, when it's an ortho. Do you think they'd write an article about how one secular kid was treated at school? Of course not.
from the article: Ultra-Orthodox school bars girl over her 'mother's immodesty'