I'm under the impression that WIMP uses "massive" in the sense of "not-massless"?

Named by astronomers, who think carbon is a metal, so what do you expect.

My favourite example comes from the development of the modern picture of the formation of the solar system, when it was suggested that giant planets often swapped places during the early days of this and other planetary systems. This idea (now widely accepted as probably true) was known as the Jumping Jupiter hypothesis.