I can see the case for the US, but I think this is exaggerated by American and western public There are some really weird phenomenon too like Punjabi Indians being strangely infatuated by Canada (kind of a tangent, but it's really remarkable - Punjabis make up 2% of India but more than half of Canada's Indian population. Canada also has 3x more Punjabis than the US, despite the latter obviously having a larger Indian population writ-large).
As far as I know, this is basically just network effects: employers in British Columbia recruited in the Punjab in the early twentieth century and the resulting Punjabi population made Canada a desirable destination for future Sikh emigrants.
