Maybe we shouldn't be painting millions of people with the same brush because of some patterns our brains happened to notice
I've anecdotally seen it happen again and again with the universities of the recruiting managers being overly represented in the candidate pool.
To note, Indians have a closer affinity to english putting them in an interesting position when moving to the US/UK (where I suppose you live). That affects wether the immigrant pool has a pretty normal social distribution or if the people getting out of their country are also used to getting out of their comfort zones. Japanese are specially affected by this, and workers that decided to go abroad will be less flocking into disporia communities.
In an ideal world you hire from a broad pool of people from the public but in reality hiring people you know tends to lower risk and a natural phenomenon.
But obviously it shouldn't be a hard rule, talent and applicable skills/personality should be what comes first every time.
If the company is entirely all Indian, over a long period of time, when they work in a diverse city then it's probably a sign they aren't looking broadly enough for talent and that is not just negatively biased socially, it's also bad for business.
The talent pool is generally over represented by Indians. I have been rejected a few times by HR (western) for not being a cultural fit.
Indian managers do not generally have the same problem, network can be a better explanation.