People with different viewpoints can't talk to each other. Or rather, on several important topics, too many people can't or won't talk to people with different views.
That assumption is probably the most toxic element contributing to the demise of intelligent public discourse and disagreement in the last decade.
I see no problem in refusing to argue with someone who is ranting against established science and refuses to look at the evidence or to reproduce the scientific results themselves.
I.e. climate denialism is usually an expression of anti-establishmentarianism married with a fear of downward mobility.
And, in fact, someone who genuinely considers that all viewpoints have equivalent value should be more willing to consider different viewpoints, not less.