Structurally, they're really tightly packed, reinforced hairs with bodily resins and oils on, but you're not going to walk up to somebody that looks like a bird and say something like "Gee, your fur sure looks shiny today!" unless you're a biology major sharing uncomfortable fun facts about other peoples' races at parties...
Besides, even if they were feathers, what of it? Reptiles had feathers, once, probably.