Maybe, maybe not. Soot is very hard to control.
I bet you had never heard of the practice of "blowing soot", and I bet they still do it at midnight.
ping
Granted that soot is hard to control and that blowing soot off various surfaces improves combustion processes to control other pollutants and reduce overall cost. I'll bet they did it at midnight so they didn't have to field calls.
What set me off was the implication that the power company is somehow irresponsible. Because we have centralized power production we have less pollution overall than we did when everyone burned whatever and the power production we have keeps getting cleaner by little tiny steps. When you burn things to get energy you will have unwanted byproducts be they soot, fly ash, heat, or radioactive compounds. Question is which poses least overall risk compared to benefits.