It's just that in the Netherlands significant amount of political discourse has been surrounding "Muslims" and "Islamification" in the last 15 years, so it makes sense for me personally. Anything could work really, "Arabs", "gays", "women", "gingers", or whatever else makes sense for you. The point is better understanding how the message is perceived, and is mostly an emotional thing. Exact accuracy regarding ethnicity and such doesn't really matter here.