Earlier quoted context omitted.
People laugh at this, but anthracite genuinely is cleaner than other coal in every regard save CO2 emissions. People just think it's a joke because they've come to believe that CO2 is the only coal emission worth caring about, which definitely isn't true.
No, the criticism isn't because people get caught up about CO2 -- it's because "cleaner than other coal" is a very low bar to meet to be calling something "clean" full stop. Also "clean coal" is not a type of coal being burnt (although that does matter too) but pollution control systems added to coal plants.
Anthracite, in these regards, is very different from bituminous coal.