Yeah, but why does it matter when they come to the US? Shouldn't hindus who immigrated earlier have an upper hand, both in income and education, regardless of social status of new immigrants? Maybe it's because immigration from India to the US is somewhat recent phenomena?
Technically, when talking about language, throw all your rules and logic out the window. :)
http://en.wikipedia.org/wiki/Linguistic_prescription
http://en.wikipedia.org/wiki/Descriptive_linguistics
It's great fun to find out when someone is inclined in one of those directions, because they go out of their way to justify their perspective. It's better than C++ vs. Java.
Look at the average graph, only 18% of the population make more than $100K. How many people in IT make less? I don't know too many, apart from really junior developers.
I'm sure if you plot Chinese vs Russian vs Indian immigrants, the numbers would be pretty close.
For example the Japanese community in the UK is tiny, almost all are senior execs of Japanese merchant banks or electronics companies - so average income is probably $250k. But in San Fransisco there are lots of poor 3-4 generation Japanese kids. It doesn't mean that there is anything better about the UK for Japanese immigrants
Family-based immigration is comparatively rare.
It remains to be seen (and could be a topic of further study) how well their descendants do. There is indeed a lot of pressure to do well in academics in Indian families (anyone who's watched the Spelling Bee competitions can see the disproportionate representation of kids of Indian descent), so it is possible that the subsequent generations will continue to do well; but it would still be worth studying.
Most of India doesn't care about caste; it's time that people _outside_ India stopped caring about Indians' caste too.