Better off to disagree or debate philosophically than pretend common ground can be had, clouding the situation with dishonest arguments and fabricated 'facts'.
In most political arguments with nutty theories on one side, those on the science-backed side think they are fighting for truth against ignorance. But what they are actually advocating is an implicit philosophy of deprecating personal autonomy in favor of an engineered society. This should at least be explicit, for the benefit of all.
Analyzing utility functions obviously puts oneself first, but you overstep in trying to handwave them away as only not giving "a shit about anyone else". If we wish for systems of rules to be grounded in relation to reality (rather than taking on a self-perpetuating arbitrary life of their own), then we must consider the base case of self interest. Only after that is aligned properly can we examine emergent phenomena like societal good.
Rhetoric is not quite so black and white as you seem to want to believe. The moment you mention "engineering society" huge swaths of people will stop listening to you regardless of their inclination to agree with your fundamental argument. Most people simply do not have the patience to precisely understand any argument with the accuracy that an expert in the field feels is necessary.
Note that I am not saying you have to play fast and loose with facts or fabricate anything, but simply: phrasing matters.
In most political arguments with nutty theories on one side, those on the science-backed side think they are fighting for truth against ignorance. But what they are actually advocating is an implicit philosophy of deprecating personal autonomy in favor of an engineered society. This should at least be explicit, for the benefit of all.
Analyzing utility functions obviously puts oneself first, but you overstep in trying to handwave them away as only not giving "a shit about anyone else". If we wish for systems of rules to be grounded in relation to reality (rather than taking on a self-perpetuating arbitrary life of their own), then we must consider the base case of self interest. Only after that is aligned properly can we examine emergent phenomena like societal good.