Most people assume there is such thing as a "self" and that it is okay, natural, and desirable to preference yourself when interacting with other people. Indeed, for most normies, there is only various people and their selves interacting. My autistic perspective is that there is only a system of the world, various roles that people happen to occupy, and here are my options for where I can slot into it, might as well choose the best one, but it never occurred to me that the other people in the system could be individually influenced or that you could preference your self over others. At least, until I interacted with others enough to realize that that was all they were doing.
Relatedly, most normies project this self-interest onto aspies and assume that when they are saying how the world is, they are pushing their own agenda, because in their worldview everybody has an agenda. As a result, the aspie tendency to make observations about broad sweeping systems comes off as arrogance, as preferencing themselves and their worldview over everybody else. But to an aspie, there is no such thing as arrogance, because arrogance implies that one preferences their self-worth over others, and there is no such thing as "self" or "worth", and it is nonsensical to talk about self-importance.