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Having grown up in Dearborn, I think it was because the two women are African-American converts to Islam, and the hijabs were just an excuse.
There have never been great relations between the local Arab (Muslim or Christian) and African-American communities. The former seem to have bought into a lot of preexisting American racism, the latter have seen the Arabs, about the only convenience store and small market owners in the city, as over-charging outsiders taking advantage of them.