These girls are treated as evils because Desi girls are always expected to be shown with sufficient cloths but modern Desi girls are wearing western outfits. Western outfits need less cloths in summer and as the climate is changing and the weather becomes so hot during summer so they wear less cloths which can be seen in this slide show.
The Desi Evil Girls go beauty parlors to get the western looks and most Desi people don't accept this new culture.