A friend of a friend told me that people, such as diplomat families who have to quickly settle but often relocate, will deliberately but routinely eat at the same restaurant, say, every Thursday evening. After a couple of weeks they'll find staff or other regular diners will engage with them and build relationships.
It's a bit easier as an expat because there are lots of other expats also looking to meet people. Very freshman year of college type vibe in my experience. Your problem becomes less making friends, and instead ensuring you make the right friends. There are a lot of dodgy characters in expat communities.
Being killed is probably a bit hyperbolic for most countries, but I would imagine it means that keeping such a predictable routine in a country where you are inherently a target (read: white people in many third world countries with high rates of robbery/violence) can make it easy for you to be targeted for robbery. Or, in limited places, terrorist acts. If the dishwasher's cousin is a small time local criminal and mentions the white family arrives and leaves at a super predictable time, his group of friends may get drunk one night and decide it's an easy payday.
