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.