These women are bathing outdoors because they do not have indoor baths or showers or toilets - private or shared. They are forced to urinate, defecate and bathe outdoors because they are POOR.
There is no culture of female nudity in India. Just look at the reports of film and TV censorship - no nudity allowed. The culture is deeply socially conservative - cohabitation before marriage is severely frowned upon. Outdoor bathing here is not an aspect of some FKK/naturist/nudist culture. Note that the disrobing shown here is mainly single-sex (or carefully turned away from men) not the open and mixed exposure you find in naturist/nudist places. The women (and men) try carefully to preserve their modesty and cover up as much as possible to bathe.
Apart from a few ancient temples, the only nude culture is amongst some Jain monks - the Digambara (sky-clad) who have renounced all worldly goods, including clothing, in this incarnation. The female Jain nuns are not naked - they are not considered to have reached the same level of rebirth as a male Jain skyclad monk. There are occasional Jain religious processions involving naked male monks, there are occasional rumors and semi-riots of alleged naked female processions - but these remain just rumors.
595 million people in India are so poor they do not have a toilet - not even a shared one see
http://www.unicef.in/Whatwedo/11/Eli...pen-Defecation these are the poor women who are being voyeured by zoom lenses costing more than many of their annual incomes.