I don’t understand about the potato and Hindus. The potato is huge in Indian cuisine.
I am guessing you are basing that from Indian restaurants in USA. In restaurants in India, legumes, wheat & rice are the most popular basics used.
A vegetarian Hindu co-worker of mine avoids tubers because cultivation involves digging in the earth for harvesting. She cooks up great pepper dishes for us! Potatoes would be included in a regular Hindu diet.