Well I am not an astronomer, but the story you tell feels very similar to the how other parts of physics sometimes use weird kinds of temperatures for similar

Well I am not an astronomer, but the story you tell feels very similar to the how other parts of physics sometimes use weird kinds of temperatures for similar reasons. In my field we sometimes liked to quote frequencies in Kelvins. What's and Planck-over-Boltzman between friends? > But I agree that it's not intuitive for those familiar with it. It's worse than that. The convention of using temperature usually arises from some such instrument-calibration where the temperature more-or-less exists, and is accurate. Then the same instrument gets used for things where temperature doesn't exist at all and sometimes doesn't even give a fair description of the energy scales. Yet people keep blithely reporting these things as temperatures.