There’s a smart person who explained from a cultural perspective why Indians tend to behave this way:
Different ways of dealing with the world
The underlying cultural foundation of Europeans and Americans is Christianity.
For Indians, the underlying cultural foundation is “Jugaad” — a way of navigating the world that involves constantly testing boundaries, being argumentative and unreasonable, and twisting logic in order to probe the other party’s bottom line and extract the maximum benefit for oneself.
The influence of Hindu fatalism / the concept of karma
In Hindu fatalism, whether a person enjoys good fortune or receives help from others in this life is not because the person helping them is kind, but because they accumulated good karma in a previous life.
So when you help an Indian, their internal logic is not “This person is really nice, I should be grateful,” but rather “This was something I was already entitled to. The gods simply delivered the karmic reward through your hands — you’re just the delivery guy.” Since it’s something they believe they deserve, there’s no need to be grateful. If you refuse to help, they might even complain about you.
The subconscious influence of the caste system
India is a caste-based society. In their cultural subconscious, relationships between people are not equal and reciprocal. Instead, people of lower castes are inherently expected to treat others well, be submissive, and take care of others — that is the meaning of a lower-caste existence.
Therefore, when someone is actively polite and considerate toward an Indian, in their cultural subconscious they may interpret it as: “Your caste is lower than mine, so taking care of me is your obligation.” If you don’t take good enough care of them or do something that upsets them, they may even resort to physical violence against you.