Do you deny that there are "western" dress codes that are imposed where parents impose certain--subordinate--role models? From the pleated skirts of my childhood (and long afterwards. The shop that catered for parents like mine changed ownership in 1998) to the pink Princess-stuff or Barbie stuff: the same thing, only more varied according to class.
eurogreen:

Or is a constant reminder of one's subordinate status a good thing?

You don't take the point that the ban of clothes typical of immigrants is a reminder of immigrants' subordinate status, do you? The debate, and the ban,is only about the headscarf of the immigrants, not the clothes the natives use for similar purposes. I note that the moment these clothes come into the focus you try the next externalisation "girls who are repressed by their Christian parents?" No, girls who are repressed by their "western culture" parents, and who, depending on class background, can be identified by their clothes from pleated skirts to Barbie stuff. I should think a ban on immigrants' clothes in a school environment where a subordinate status with respect to natives is neither required nor approved of.