but plastic is good
I don't think the merits or downsides of plastics have been mentioned. Sometimes it's about finding the lesser evil.
Coal doesn't need to be produced
Plastic comes from oil, and a very little oil makes a lot of plastic. It only comes from one fraction in the refining process and the rest of the fractions are sold on. Providing it's recycled, it's good.
The coal industry does use a lot (really a lot) of steel, and that is not recycles, unlike the steel used in refining which is reused.
We all like a coal fire, however the smoke from domestic coal burning poisons the air; even commercial coal burning with the newest and cleanest chimneys isn't great.