Well, the pattern isn't "random group of people get-together," it's "severe minority group get-together." Less of a warning sign and more of a general pattern. I think it makes a lot of sense to look for the familiar when you're surrounded by something that is somehow alien to you. And since the groups are often formed because of some exclusion (perceived or real), they're very rarely exclusionary themselves.

As a white male in tech, I can see how you might find it difficult to empathize with someone in that situation. Best sort of "imagine if" scenario would be if I dropped you in the middle of a foreign country and you looked around and realized that there were a few Techers there with you. You guys (and gals?) might have some beers together, and if anyone from Turkmenistanians wanted to join you, they could.