I think they migrated form hilly area and had to compete with Rajbansi and Bangali, as the time passed they became more clever according to the needs which is far away from others need, somehow they could not act according to the present environment and society. Where ever they went could not leave their past and could not mold accordingly, therefore they started this proverb.

You know about women in Bharatpur (Chitwan, ride bike and their husband sits in the back) same way they are very upfront and very smart,  I like that.