Actually, I disagree. There are plenty of examples of unadulterated evil in the world of Fallout 4. What you're describing is a text book sociopath; someone who has no empathy and views other human beings in their capacity to service their own ends. They seek, above all, control. They only cooperate insofar as it serves their needs.

We see people like that amass incredible power in our world as it exists now. But, what is perhaps most telling in the world of Fallout 4, is that none of these groups are exceptionally powerful. There is no evil conspiracy of men or a singular evil leader, because the cost of doing it yourself is prohibitively expensive. It didn't even occur to me until just now, but this is exactly what I and other ancaps have presented as an argument against warfare being perpetual and unending absent a state: it costs too damn much to fund an army. This is especially true if most of the population is armed themselves, as is the case in Fallout 4.

Perhaps the reason there are no absolutely evil answers is because, absent a death wish, absolute evil doesn't have the capability of thriving. Perhaps without an established state infrastructure, evil is confined, contained, and relatively easy to deal with.