Thats because Indians in US don't represent the average Indian (or any Asiam minority) for that matter.
The Indians in the US for the most part are the cream of the crop of India. They were selected for unis and colleges against all other Indians, best scores, filtered with tough visa interviews, then they go thru h1b struggle, sponsorship. So the remaining people are the best India offers (which ironically the US drains). That's why the stereotype is of a successful nerd.
In Canada, the Indians they take are the Average Punjeet, so the stereotypes are different and probably way worse. Just my observation