They come built in with a set of heuristics that help them interact with other NT minds very well with very little cognitive effort, so why spend it if you don't need to? There's a certain perverse genius to it which you'd see if you spend any time around profoundly NT people: for example those who fit the "theatre kid" archetype, or even skilled marketers. They can shape the trajectory of an interpersonal relationship in real time as easily as we breathe.

Expending large amounts of cognitive effort to better understand and deal with others can be exhausting. We do it because we have to just to survive. The benefit is we have a lot of uncommitted neural capacity potentially freed up for other things, like experimenting with computers. But it's a stiff price to pay, and in the EEA it's advantageous to be able to participate in a cohesive group without thinking much about it. Our brains are our most energy-hungry organs, and sustenance could get scarce...