1. The ability to start and control fire is a defining feature of the species, without which spread to polar and high-elevation climates would have been impossible. Fire was a fundamental defense against predators, allowed humans to eat foods previously unpalatable, and as a result it's impossible to imagine any group of humans living and surviving without fire.
2. Language is not a unique feature of the human species, relatively complex verbal communication has been found in whales and parrots at least. Other intelligence-based activity (tool use) are also found in crows, chimpanzees, etc. This undermines the rationale for 'sapiens' as intelligence is not unique to humans.
3. The steady destruction of the biosphere's oxygen-generating capability along with injection of vast amounts of carbon and nitrogen and pollutants into the air and water doesn't really seem that wise. Homo ignis would at least acknowledge the potentially self-destructive nature of human behavior.