wearing simple sober dress and minimal makeup is the part of our culture and short skirts and different makeups is imported from western culture. We Indians are adopting every thing from western culture, though we cant say that western culture is bad but we should import good habits from western people like how clean they live, keep surroundings clean, live in well mannered way, but should not replace everything of our culture, like wearing short dresses, leaving our morals and values.

Irrespective of the cultures and their origin, a good thing that enshrines our lives should be taken and use it to our advantage.

The single point here is that the school is not the coeducation, it is girls only, so there must be some other aspects in consideration for this as it seems some strange reason given by the school, as it is one of the costliest boarding school. 

It is not strange at all. the article clearly says that it is a policy matter of the school.