The sound of these engines is being overrated. Presumably because everyone's expectations were so low, since it is 50% Formula E after all.
If the MGU-H wasn't made illegal , everyone would be running them. Because the system weighs 8kg and allows the battery to be smaller. The lack of MGU-H also makes the car less efficient.
So there's a little something for nobody. The environmentalist fans get a less efficient car. And the purist racers get something heavier.