In addition, second, third and further consequences of their actions appear to never feature in their decision-making,
What is to blame? Most obviously it is an education system that (via the Oxford politics, philosophy and economics degree above all else) teaches that markets dominate economies, governments should back away from interfering to the greatest extent possible, and there are no externalities (i.e., those second and third tier consequences of decisions that very obviously do exist) because markets can always price them.
He is, actually, insane, isn’t he? The entire point of even the word externality is something that is external to markets and thus unpriced. By the very use of the word we are insisting that markets cannot and do not price them.