Don't you think this is partially true actually for not using left hand and we always PREFER to use right hand for eating and other good work. But we could easily reply that wiping shit with toilet paper only and not using water after that is even MORE unhygienic practice and therefore in west nobody uses hand for eating. They have many other very unhygienic practice like dipping used spoon in common food bowl or testing directly from spoon and again dipping it in the pan etc. Everybody visiting foreign countries will understand that at least the middle/upper class Indians are actually more clean than many rich foreign countries and we cannot think of taking bath (even at 0 deg C) once a week.
