well, everyone has its own way of thinking, own experiences, i dont understand this parda pratha too, but i've seen that its "biased",
i am saying this after my own experience, i've a moderate mix traditional family, every type of people, some of my relatives are in "village" , some like us are in "shahar" so i can see both trends,
in our family there is no pratha system,means my grandmother was too old but she too didnt want that her "bahu" means my mom do parda, but whenever she used to go to village she herself did parda, to her elders, & alll my sister-in-laws, my elder anti do the same in village, but whenever they come to us, means in town they dont do this,
even my mom, do parda when ever she goes to village, or any elder person comes from the village,
Moreover my" bua ji" very well educated , never cover her head in front of her father-in-law, when he comes to town, but when she goes to village , she cover whole of her face, like others in village,and her all in-laws , are well educated, even mother-in-law is teacher, and she never says her daugther-in-laws to cover their faces.But one has itself realize that if i'll not do this the i'd be the point of attention in eyes of others, not in eyes of my own family, but for neighbours, and nobody wants to do that.
My point is that this is not only the education, or the restrictions from the in-laws, which make one to do this parda things, its like "jaisa desh vaisa bhesh" means as the place as the behaviour,
Its the human nature, it comes from one's inside that if we are here, then we should do this, or that,
ok, just take another look, when we are in our country, we wear our's tradition dresses, like salwar kamiz, saaris, jeans, etc, etc, but when we come to western country like in USA, as many of us comes here, we dont like to wear salwar kamiz, saaris,and only wear according to this country taste, why , because we think that this will be awkward, to be different, if we will wear our's tradition dresses, then everyone will look at us, and its really not anybody wants, so "jaisa desh vaisa bhesh"
I agree that this parda pratha is not logical, but as the matter of fact, this is good for women's in the concern of their beauty, because as we all know that when we go in bright sunlight , we always cover our face, so that it doesnt harm, we cover our face when there is windy day, or like that, so the women who covers their face most of the time, their face definetly glows, and its my personnal experience, my all sister-in-laws, their faces always glow, without applying anything, as in village we all know that women dont put make up or anything.
SO everthing has its positive and negative points.