“They’re dieing people!! What difference does it make what they do?! If it makes them feel better, even if it’s in their own mind, what does it matter?”
The self-righteous tend to think in absolute (vs. relative) terms.
My mom smoked until she more or less lost her mind from the brain tumor and forgot she smoked. My brother would gripe at her about it. I told him shut up and leave her alone. What difference does it make now? A year later she was gone.