Timid, un-self-promoting Indian-in-the-UK here.

Yours is a broad generalisation, and one that has hurt my career in the past because of senior people who inevitably follow this chain of reasoning: "Indians are good at playing the self-promotion game --> shrikant is Indian, and he's not bigging himself up enough --> he must not be good enough --> meh, average rating, let's move on to the next person".

This hasn't happened everywhere, so I suppose it is down to organisational culture as well.

But also I guess my point is: even if broad generalisations hold "true", it's not cool to apply it to an individual.