It's one of the same reasons why people get pissed off at truths about their own political parties. It's their "feels" and being comfortable with something that seems to be a part of their existence or heritage or tradition.
No smoke is good for your lungs and health. It's an "obvious" truth. We can turn around and tell Harris, despite it's less harmful nature, that his wanting to burn gas has it's own problems in terms of the environment and the collective human health in terms of corporations, war, and climate change etc. I guess it all just depends on WHO it is hurting. I like Harris, but this seems a bit hypocritical to me.