> Someone noticed that we were puzzled by this a told us that this is due to Indian culture.

You may have been misled there because Indian culture isn't homogenous. Even from a Hindu thought perspective, as per Chapter 17, Sloka 20 of the Bhagavad Gita, Krishna says

दातव्यमिति यद्दानं दीयतेऽनुपकारिणे। देशे काले च पात्रे च तद्दानं सात्त्विकं स्मृतम्।।17.20।।

While I'm not an expert, loosing translated, it means that one must do charity without expecting anything in return. Doing so, in the right manner and in the right place is the epitome of goodness.

I interpret that to be a pretty clear moral imperative to help someone in genuine need.