It is the culture and I say this as an Indian. There are poorer nations surrounding India which are much cleaner - example: Srilanka, Nepal, Bhutan etc.
I won't go into what exact part of culture results in this because it will upset a lot of people - but I do ask Indians reading my comment to ponder upon it without becoming defensive
Sri Lanka, Nepal and Bhutan do not have any cities with 5+ million people. In fact, the most populated cities in those nations do not even exceed 1 million people.
I won't go into what exact part of culture results in this because it will upset a lot of people - but I do ask Indians reading my comment to ponder upon it without becoming defensive